Answer:
a. t = 2.48 will be a period within 2009.
b. 56.16 million
Step-by-step explanation:
Here is the complete question
Apple introduced the first iPod in October 2001. Sales of the portable music player grew slowly in the early years but began to grow rapidly after 2005. But the iPod era is coming to a close. Smartphones with music and video
Apple introduced the first iPod in October 2001. Sales of the portable music player grew slowly in the
END OF THE IPOD ERA
players are replacing the iPod, along with the category of device it helped to create. Sales of the iPod worldwide from 2007
through 2011 (in millions) were
approximately
N(0= -2.65t2 + 13.13t+ 39.9 (0 < t< 4)
in year t, where t= 0 corresponds to 2007. Show that the worldwide sales of the iPod peaked sometime in 2009. What was the approximate largest number of iPods sold worldwide from 2007 through 2011?
a. Show that the worldwide sales of the iPod peaked sometime in 2009
N(t) = -2.65t² + 13.13t + 39.9
To find the maximum value of N(t), we find dN(t)/dt and equate it to zero
dN(t)/dt = d[-2.65t² + 13.13t + 39.9]/dt
dN(t)/dt = -5.3t + 13.13 = 0
-5.3t = - 13.13
t = -13.13/(-5.3)
t = 2.477
t ≅ 2.48
d²N(t)/dt² =d[-5.3t + 13.13]/dt = -5.3 < 0. So, t = 2.48 is a maximum point
Since t = 2 is 2009 and t = 3 is 2010, t = 2.48 will be a period within 2009.
b. What was the approximate largest number of iPods sold worldwide from 2007 through 2011?
The approximate largest number of ipods sold is when t = 2.48
N(2.48) = -2.65(2.48)² + 13.13(2.48) + 39.9
N(2.48) = -16.29856 + 32.5624 + 39.9
N(2.48) = 56.16384
N(2.48) ≅ 56.16 million
GIVING BRAINLIEST TO THE FIRST PERSON TO ANSWER!
A 16-inch piece of string is 40.64 centimeters long. To the nearest 0.01 centimeter, how long will a 42-inch price of string be?
A. 56.64 cm
B. 82.64 cm
C. 106.68 cm
D. 1,706.88 cm
Please show ALL work! <3
Answer:
106.68 centimeters
Step-by-step explanation:
40.64 cm/16 in = x cm/42 in
Cross multiplying, we get:
16x = 40.64(42)
16x = 1706.88
x = 106.68 centimeters
Which defines a line segment?
two rays with a common endpoint
O a piece of a line with two endpoints
O a piece of a line with one endpoint
all points equidistant from a given point
Answer:
O a piece of a line with two endpoints
Step-by-step explanation:
O a piece of a line with two endpoints
A piece of a line with two endpoints.
What is a line segment?In geometry, a line segment is a part of a line this is bounded by distinct end points and includes every point on the line this is between its endpoints.
What are the examples of line segments in real life?A ruler, a scale, a stick, a boundary line.Learn more about line segments here https://brainly.com/question/2437195
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URGENT At Garcia's Bike Rentals, it costs $ 36 to rent a bike for 9 hours. How many hours of bike use does a customer get per dollar?
Answer:
.25 hour / dollar
Step-by-step explanation:
We want hours per dollar
9 hours/ 36 dollars
1/4 hour / dollar
if given the diameter how can you find the radius
Answer:
Divide the diameter by 2.
Step-by-step explanation:
The radius of any circle is always the end to the center.
The diameter is a point of the circle to the opposite side.
This means that the diameter is twice the size of the radius, so to find the radius from the diameter, divide the diameter by 2.
Hope this helped!
Answer:
Divide the diameter by 2. d/2=r
Step-by-step explanation:
If a diameter has been given instead of a radius, you can find the radius by dividing the diameter by 2, for example.
If the diameter was 10, the radius would 10/2=5.
Find (fºg)(2) and (f+g)(2) when f(x)= 1/x and g(x) = 4x +9
[tex](f\circ g)(2)=\dfrac{1}{4\cdot2+9}=\dfrac{1}{17}\\\\(f+g)(2)=\dfrac{1}{2}+4\cdot2+9=\dfrac{1}{2}+17=\dfrac{1}{2}+\dfrac{34}{2}=\dfrac{35}{2}[/tex]
Sugar, flour, and oats are stored in three drawers. The first drawer is labeled "oats", the second is labeled, "flour", the third is labeled "oats or flour". The label of each drawer does not correspond to what is stored inside of it. In which drawers is what stored?
Answer:
first = flour, second = oats, third = sugar
Step-by-step explanation:
Since the labels are "wrong", we know that the third drawer doesn't have oats or flour, therefore it has sugar. Since the first doesn't have oats, it must have flour and that makes the second drawer oats.
Answer:
first drawer has flour, second has oats, third is sugar
Step-by-step explanation:
on the first drawer, it is labelled oats, so it cannot be oats. on the second it cannot be flour, and on the third it cannot be oats or flour, which means it HAS to be sugar leaving oats and flour to be in either the first, or second.
i know it may sound a little confusing but please let me know if you dont understand
22 tons is equivalent to ______ kilograms.
Answer:
20000 kg
Step-by-step explanation:
Recall that 1 kg = 2.2 lb approximately. Then:
22 tons 1 kg 2000 lb
------------ * ------------ * -------------- = 20000 kg
1 2.2 lb 1 ton
Find the probability of winning a lottery with the following rule. Select the winning numbers from 1, 2, . . . ,34 . (In any order. No repeats.)
Complete Question
Find the probability of winning a lottery with the following rule. Select the six winning numbers from 1, 2, . . . ,34 . (In any order. No repeats.)
Answer:
The probability is [tex]P(winning ) = 7.435 *10^{-7}[/tex]
Step-by-step explanation:
From the question we are told that
The total winning numbers n = 34
The total number to select is r = 6
The total outcome of lottery is mathematically represented as
[tex]t_{outcome}) = \left n } \atop {}} \right. C_r[/tex]
[tex]t_{outcome}) = \frac{n! }{(n-r )! r!}[/tex]
substituting values
[tex]t_{outcome}) = \frac{ 34 ! }{(34 - 6 )! 6!}[/tex]
[tex]t_{outcome}) = \frac{ 34 ! }{28 ! 6!}[/tex]
[tex]t_{outcome}) =1344904[/tex]
The number of desired outcome is
[tex]t_{desired} = 1[/tex]
this is because the desired outcome is choosing the six winning number
The probability of winning a lottery is mathematically represented as
[tex]P(winning ) = \frac{t_{desired}}{t_{outcome}}[/tex]
substituting values
[tex]P(winning ) = \frac{1}{1344904 }[/tex]
[tex]P(winning ) = 7.435 *10^{-7}[/tex]
Compute (3/4)*(8/9)*(15/16)*(24/25)*(35/36)*(48/49)*(63/64)*(80/81)*(99/100) Express your answer in the simplest way possible. (Suggestion: First, try computing 3/4*8/9 then 3/4*8/9*15/16 and so on. Look for patterns.
Answer:
[tex](\frac{3}{4})*(\frac{8}{9})*(\frac{15}{16})*(\frac{24}{25})*(\frac{35}{36})*(\frac{48}{49})*(\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}) = \frac{11}{20}[/tex]
Step-by-step explanation:
Given
[tex](\frac{3}{4})*(\frac{8}{9})*(\frac{15}{16})*(\frac{24}{25})*(\frac{35}{36})*(\frac{48}{49})*(\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100})[/tex]
Required
Simplify
For clarity, group the expression in threes
[tex]((\frac{3}{4})*(\frac{8}{9})*(\frac{15}{16}))*((\frac{24}{25})*(\frac{35}{36})*(\frac{48}{49}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
Evaluate the first group [Divide 8 by 4]
[tex]((\frac{3}{1})*(\frac{2}{9})*(\frac{15}{16}))*((\frac{24}{25})*(\frac{35}{36})*(\frac{48}{49}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
[Divide 9 by 3]
[tex]((\frac{1}{1})*(\frac{2}{3})*(\frac{15}{16}))*((\frac{24}{25})*(\frac{35}{36})*(\frac{48}{49}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
[tex]((\frac{2}{3})*(\frac{15}{16}))*((\frac{24}{25})*(\frac{35}{36})*(\frac{48}{49}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
[Divide 15 by 3]
[tex]((\frac{2}{1})*(\frac{5}{16}))*((\frac{24}{25})*(\frac{35}{36})*(\frac{48}{49}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
[Divide 16 by 2]
[tex]((\frac{1}{1})*(\frac{5}{8}))*((\frac{24}{25})*(\frac{35}{36})*(\frac{48}{49}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
[tex](\frac{5}{8})*((\frac{24}{25})*(\frac{35}{36})*(\frac{48}{49}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
Evaluate the second group [Divide 35 and 25 by 5]
[tex](\frac{5}{8})*((\frac{24}{5})*(\frac{7}{36})*(\frac{48}{49}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
[Divide 49 by 7]
[tex](\frac{5}{8})*((\frac{24}{5})*(\frac{1}{3})*(\frac{4}{7}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
[Divide 24 by 3]
[tex](\frac{5}{8})*((\frac{8}{5})*(\frac{1}{1})*(\frac{4}{7}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
[tex](\frac{5}{8})*((\frac{8}{5})*(\frac{4}{7}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
Merge the first and second group
[tex]((\frac{5}{8})*(\frac{8}{5})*(\frac{4}{7}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
[tex](1*(\frac{4}{7}))*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
[tex](\frac{4}{7})*((\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}))[/tex]
Evaluate the last group [Divide 99 by 9]
[tex](\frac{4}{7})*((\frac{63}{64})*(\frac{80}{9})*(\frac{11}{100}))[/tex]
[Divide 63 by 9]
[tex](\frac{4}{7})*((\frac{7}{64})*(\frac{80}{1})*(\frac{11}{100}))[/tex]
[Divide 64 and 80 by 8]
[tex](\frac{4}{7})*((\frac{7}{8})*(\frac{10}{1})*(\frac{11}{100}))[/tex]
[Divide 10 and 4 by 2]
[tex](\frac{4}{7})*((\frac{7}{4})*(\frac{5}{1})*(\frac{11}{100}))[/tex]
[Divide 100 by 5]
[tex](\frac{4}{7})*((\frac{7}{4})*(\frac{1}{1})*(\frac{11}{20}))[/tex]
[tex](\frac{4}{7})*((\frac{7}{4})*(\frac{11}{20}))[/tex]
[tex](\frac{4}{7})*(\frac{7}{4})*(\frac{11}{20})[/tex]
[tex]1*(\frac{11}{20})[/tex]
[tex]\frac{11}{20}[/tex]
Hence;
[tex](\frac{3}{4})*(\frac{8}{9})*(\frac{15}{16})*(\frac{24}{25})*(\frac{35}{36})*(\frac{48}{49})*(\frac{63}{64})*(\frac{80}{81})*(\frac{99}{100}) = \frac{11}{20}[/tex]
Two sides of a triangle are equal length. The length of the third side exceeds the length of one of the other sides by 3 centimeters. The perimeter of the triangle is 93 centimeters. Find the length of each of the shorter sides of the triangle
Answer:
30 cm
Step-by-step explanation:
let x be the lenght of the two sides of equal lenghts, so the other is x+3
and the perimeter is x+x +x +3
P=3x+3
P=3(x+1)
93=3(x+1)
31=x+1
x=30
so the shorter sides are of 30 centimeters and the longest is 33
James has a total of 66 dollars in his piggy bank. He only has one dollar bills and two dollar bills in his piggy bank. If there are a total of 49 bills in James's piggy bank, how many one dollar bills does he have?
Answer:
32 one-dollar bills.
Step-by-step explanation:
Let x represent one-dollar bills and y represent two-dollar bills.
He has a total of 49 bills. Therefore:
[tex]x+y=49[/tex]
The total amount of money James has is 66. x is worth one dollar, while y is worth two dollars. Therefore:
[tex]1x+2y=66\\x+2y=66[/tex]
We have a system of equations. Solve by substitution:
[tex]x+2y=66\\x+y=49\\x=49-y\\(49-y)+2y=66\\y=17\\x=49-17=32[/tex]
Therefore, James has 32 one-dollar bills and 17 two-dollar bills.
Checking:
[tex]32(1)+17(2)\stackrel{?}{=}66\\32(1)+17(2)\stackrel{\checkmark}{=}66\\\\32+17\stackrel{?}{=}49\\49\stackrel{\checkmark}{=}49[/tex]
It takes amy 8 minutes to mow 1/6 of her backyard. At that rate how many more minutes will it take her to finish mowing her backyard
Answer:
40 minutes
Step-by-step explanation:
If it takes her 8 minutes to mow 1/6 of it, we can find the total amount of time it will take by multiplying 8 by 6, since 1/6 times 6 is 1 (1 represents the whole lawn mowed)
8(6) = 48
The question asks for how many more minutes it will take, so subtract 48 by 8.
48 - 8 = 40
= 40 minutes
Answer:
40 minutes
Step-by-step explanation:
We can use ratios to solve
8 minutes x minutes
------------------- = ----------------
1/6 yard 1 yard
Using cross products
8 * 1 = 1/6 x
Multiply each side by 6
8*6 = 1/6 * x * 6
48 = x
48 minutes total
She has already done 8 minutes
48-8 = 40 minutes
Use the graph showing Phillip's account balance to answer the question that follows. ^
What is the interest rate on Phillip's account?
A - 3.3%
B - 6.7%
C - 9.0%
D - 15.3%
Answer:
A - 3.3%
Step-by-step explanation:
From the graph
Where x= 0
Amount =$ 450
It shows that$450 is the capital
Then
When x= 3
Amount=$494.55
So interest generated within 3 years
= $494.55-$450
=$ 44.55
When x= 9
Amount = $583.65
So interest generated within 9 years
= $583.65-$450
=$ 133.65
PRT/10= Interest
450*x*3/100= 44.55
1350x= 4455
X= 4455/1350
X= 3.3
So the rate is =3.3%
The scale on a scale drawing is 1 : 30. What should you do with each measurement on the drawing to get the actual dimensions? Provide an example of a drawing that uses this scale. Include both the original and new dimensions.
Answer:
see below
Step-by-step explanation:
For the first question, you should multiply the scale dimension by 30 to get the actual dimension. This is because the scale is 1:30 where the scale dimension is the 1 and the actual dimension is 30, so therefore, the scale dimension is 1/30th of the actual dimension, so to get the actual dimension, we can multiply the scale dimension by 30. I'm not totally sure how to attach pictures from my phone on my computer (sorry) but an example of a drawing could be two rectangles, the first (this is the scale drawing) having dimensions of 1 by 2 units and the second (this is the actual drawing) having dimensions of 30 by 60 units. I hope this helps!
Karim has two investments, one in Company A, and another in Company B. Karim purchased 3,000 shares in company A at $2.65 per share. Since purchasing the shares, the price per share increased to $2.95 per share, after which point Karim decided to sell, realizing a profit. At the same time, Karim purchased 2,000 shares in Company B at $1.55 per share. Since purchasing the shares, the share price fell to $1.30 per share, after which Karim decided to sell the shares, suffering a loss. Karim is required to pay tax at a rate of 28% on the combined profit from both investments. Calculate how much tax Karim must pay.
Answer:
A:$2478
B:$728
Total:$3206
Step-by-step explanation:
2.95x3000=8850
1.30x2000=2600
8850x0.28=2478
2600x0.28=728
2478+728=3206
Find the polynomial for the area.
The area is
Answer: ¹/₂( x² - 10y² + 10xy - xy )
Step-by-step explanation:
From the diagram area of the triangle = ¹/₂ ˣ base ˣ height
where the base = x + 10y and the height = x - y
Therefore putting these into the formula above
Area = ¹/₂ [( x + 10y )( x -y )]
= ¹/₂( x² - xy + 10xy - 10y²)units²
= ¹/₂( x² - 10y² + 10xy - xy )
This year Alex’s age is 1/6 of his dads. Four years later, Alex’s age is 1/4 of his dads. How old is Alex and his dad this year?
Answer:
This year:
dads: 36 years
Alex: 6 years
Step-by-step explanation:
a = d/6
a+4 = (d+4)/4
a = Alex´s actual age
d = actual age of the dad
d/6 + 4 = (d+4)/4
4{(d/6) + 4} = d+4
4*d/6 + 4*4 = d+4
4d/6 + 16 = d + 4
4d/6 = d + 4 - 16
4d = (d-12)*6
4d = 6*d +6*-12
4d = 6d - 72
4d - 6d = -72
-2d = -72
d = -72/-2
d = 36
a = d/6
a = 36/6
a = 6
probe:
a+4 = (d+4)/4
6 + 4 = (36+4)/4
10 = 40/4
The accompanying summary data on total cholesterol level (mmol/l) was obtained from a sample of Asian postmenopausal women who were vegans and another sample of such women who were omnivores.
Diet Sample Size Sample Mean Sample SD
Vegan 85.00 5.20 1.08
Omnivore 91.00 5.65 1.10
Calculate a 99% CI for the difference between the population mean total cholesterol level for vegans and population mean total cholesterol level for omnivores. (Use μvegan−μomnivore). Round to three decimal places.)
Interpret the interval.
a. We are 99% confident that the true average cholesterol level for vegans is less than that of omnivores by an amount within the confidence interval.
b. We are 99% confident that the true average cholesterol level for vegans is greater than that of omnivores by an amount within the confidence interval.
c. We are 99% confident that the true average cholesterol level for vegans is greater than that of omnivores by an amount outside the confidence interval.
d. We cannot draw a conclusion from the given information.
Answer: hey
Step-by-step explanation:
A population consists of 100 elements. We want to draw a simple, random sample of 20 elements from this population. On the first selection, the probability of any particular element being selected is ____.
Answer:
1/5Step-by-step explanation:
Probability is the likelihood or chance that an event will occur.
Probability = expected outcome of event /total outcome
Since the population consists of 100 elements, the total outcome of event = 100.
If random sample of 20 element is drawn from the population, the expected outcome = 20
On the first selection, the probability of any particular element being selected = 20/100 = 1/5
1f 12% of x is equal to 6% of y, then 18% of x will be equal to how much percent ofy?
Answer:
9%
Step-by-step explanation:
12x=6y eq 1
18x=9y eq 2
An economist is interested in studying the spending habits of consumers in a particular region. The population standard deviation is known to be $1,000. A random sample of 50 individuals resulted in an average expense of $15,000. What is the width of the 99% confidence interval for the mean of expense? a. 364.28 b. 728.55 c. 329.00 d. 657.99
Answer:
The width is [tex]w = \$ 729.7[/tex]
Step-by-step explanation:
From the question we are told that
The population standard deviation is [tex]\sigma = \% 1,000[/tex]
The sample size is [tex]n = 50[/tex]
The sample mean is [tex]\= x = \$ 15,000[/tex]
Given that the confidence level is 99% then the level of significance is mathematically represented as
[tex]\alpha = 100 - 99[/tex]
=> [tex]\alpha = 1\%[/tex]
=> [tex]\alpha = 0.01[/tex]
Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from the normal distribution table, the value is
[tex]Z_{\frac{\alpha }{2} } = Z_{\frac{0.01 }{2} } = 2.58[/tex]
Generally margin of error is mathematically represented as
[tex]E = Z_{\frac{\alpha }{2} * \frac{\sigma }{\sqrt{n} }[/tex]
substituting values
[tex]E = 2.58 * \frac{1000 }{\sqrt{50} }[/tex]
[tex]E = 2.58 * \frac{1000 }{\sqrt{50} }[/tex]
[tex]E = 364.9[/tex]
The width of the 99% confidence interval is mathematically evaluated as
[tex]w = 2 * E[/tex]
substituting values
[tex]w = 2 * 364.9[/tex]
[tex]w = \$ 729.7[/tex]
If A = {2,4,6,8,10) and B = [4,8,10), then which of the following statements is false?
A n B = B
B C B
A C B
A C B because all elements of A are not found in B
How do you evaluate this?
[tex]_6C_3=\dfrac{6!}{3!3!}=\dfrac{4\cdot5\cdot6}{2\cdot3}=20[/tex]
Match the base to the corresponding height.
Base (b)
Height (h)
b
h
h
b
The base 1 is matched with height 2, base 2 is matched with height 3 and base 3 is matched with height 1. The base to the corresponding height is matched in the attached figure.
What is a triangle?Triangle is the closed shaped polygon which has 3 sides and 3 interior angles. The height of the triangle is the dimension of the elevation from the opposite peak to the length of the base.
Thus, the base 1 is matched with height 2, base 2 is matched with height 3 and base 3 is matched with height 1. The base to the corresponding height is matched in the attached figure.
In the given figure, three triangles is shown with base and height. Here,
The base 1 is matched with height 2, as the height shown in figure 2 is the dimension of the elevation from the opposite peak to the length of the base 1.Similarly, base 2 is matched with height 3.Base 3 is matched with height 1.
Thus, the base 1 is matched with height 2, base 2 is matched with height 3 and base 3 is matched with height 1. The base to the corresponding height is matched in the attached figure.
Learn more about the base and height of the triangle here;
https://brainly.com/question/26043588
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For a closed rectangular box, with a square base x by x cm and height h cm, find the dimensions giving the minimum surface area, given that the volume is 18 cm3.
Answer:
∛18 * ∛18 * 18/(∛18)²
Step-by-step explanation:
Let the surface area of the box be expressed as S = 2(LB+BH+LH) where
L is the length of the box = x
B is the breadth of the box = x
H is the height of the box = h
Substituting this variables into the formula, we will have;
S = 2(x(x)+xh+xh)
S = 2x²+2xh+2xh
S = 2x² + 4xh and the Volume V = x²h
If V = x²h; h = V/x²
Substituting h = V/x² into the surface area will give;
S = 2x² + 4x(V/x²)
Since the volume V = 18cm³
S = 2x² + 4x(18/x²)
S = 2x² + 72/x
Differentiating the function with respect to x to get the minimal point, we will have;
dS/dx = 4x - 72/x²
at dS/dx = 0
4x - 72/x² = 0
- 72/x² = -4x
72 = 4x³
x³ = 72/4
x³ = 18
[tex]x = \sqrt[3]{18}[/tex]
Critical point is at [tex]x = \sqrt[3]{18}[/tex]
If x²h = 18
(∛18)²h =18
h = 18/(∛18)²
Hence the dimension is ∛18 * ∛18 * 18/(∛18)²
5,829 in expanded form
Answer:
5,000 + 800 + 20 + 9
Step-by-step explanation:
The definition of expanded form is to "write the value of each digit then add them together to find the sum." - study.com
That is exactly what we did above.
If we write it going up and down like below, we can pull the individual values:
5 000
8 00
2 0
9
I hope this helps!
33 points
1. A sandwich vendor offers a choice of hamburger, chicken, or fish on
either a plain or sesame seed bun. How many different types of
sandwiches are there to choose from?
*
4
6
12
3
Answer:
6 sandwiches to choose from because
3×2 = 6
Explain how to solve the inequality (x + 1)(x – 2) ∙ (x – 3) > 0. Explain in your own words, each step necessary to solve the inequality, making sure to follow the proper order of operations. Is this inequality accurate? Explain why or why not.
Answer:
[tex]x > -1[/tex] or
[tex]x > 2[/tex] or
[tex]x > 3[/tex]
Step-by-step explanation:
Given
[tex](x + 1)(x - 2) (x - 3) > 0[/tex]
Required
Solve; with steps
[tex](x + 1)(x - 2) (x - 3) > 0[/tex]
Start by splitting the inequality as follows
[tex]x + 1 > 0[/tex] or [tex]x - 2 > 0[/tex] or [tex]x - 3 > 0[/tex]
Solve the inequalities one after the other
Solving: [tex]x + 1 > 0[/tex]
Subtract 1 from both sides
[tex]x + 1 - 1 > 0 - 1[/tex]
[tex]x > -1[/tex]
Solving: [tex]x - 2 > 0[/tex]
Add 2 to both sides
[tex]x - 2 +2 > 0 +2[/tex]
[tex]x > 2[/tex]
Solving: [tex]x - 3 > 0[/tex]
Add 3 to both sides
[tex]x - 3 +3> 0+3[/tex]
[tex]x > 3[/tex]
Hence, the solution to the inequality is
[tex]x > -1[/tex] or
[tex]x > 2[/tex] or
[tex]x > 3[/tex]
Nancy believes that the average running time of movies is equal to 140 minutes. A sample of 4 movies was taken and the following running times were obtained. Assume the distribution of the population is normally distributed. 150 150 180 170
a. State the null and alternative hypotheses.
b. Using a critical value, test the hypothesis at the 10% level of significance.
c. Using a p-value, test the hypothesis at the 10% level of significance.
d. Using a confidence interval, test the hypothesis at the 10% level of significance.
e. Could a Type II error have been committed in this hypothesis test?
Answer:
a; H0: u= 140 Ha: u ≠ 140 two tailed test.
b. Therefore reject H0 as t= 3 ≠ t≤ t ( ∝/2) (n-1) =2.353 or
3 > t ( ∝/2) (n-1) =2.353
c. If we check from the table the p- value is 0.6 which lies between 0.1 and 0.05 therefore reject H0.
d. Again reject H0 as 140 < 150.163
e. A type II error has not been committed as H0 is rejected.
Step-by-step explanation:
We formulate the null and alternative hypotheses as
a; H0: u= 140 Ha: u ≠ 140 two tailed test.
For a two tailed test the significance level ∝= 0.1 the critical region is given by
t ≤ t ( ∝/2) (n-1) and t > t ( ∝/2) (n-1)
So the critical region will be
t≤ t ( ∝/2) (n-1) =2.353
where
t= x` - u / s/ √n
Sr. No X X²
1 150 22500
2 150 22500
3 180 32400
4 170 28900
∑ 650 106,300
X`= ∑x/n = 650/4= 162.5
s²= 1/n-1 (x-x`)²= 1/n-1 [ ∑x² -(∑x)²/n ]
= 1/3[106,300 -650²/4] = 225
s= 15
Putting the values in the above equation
t= 162.5- 140/ 15/ √4
t= 3
So calculated value of t= 3
b. Therefore reject H0 as t= 3 ≠ t≤ t ( ∝/2) (n-1) =2.353 or
3 > t ( ∝/2) (n-1) =2.353
c. If we check from the table the p- value is 0.6 which lies between 0.1 and 0.05 therefore reject H0.
d. a 90% confidence interval based on the calculated values will be
x`± 1.645 (s)/ √n
Putting the values
162.5 ±1.645 ( 15/2)
162.5 ±12.3375
174.84 , 150.163
d. Again reject H0 as 140 < 150.163
e. A type II error has not been committed as H0 is rejected.
Find the equation of the para bola that has zeros of x = -2 and x = 3 and a y-intercept of (0,-30)
Answer:
y = 5x^2-5x-30
Step-by-step explanation:
A parabola with x-intercepts at (-2,0) and (3,0) has the equation
y = a(x+2)(x-3)
where a is to be determined.
We know that it passes through the point (0,-30), so
-30 = a(0+2)(0-3) = -6a
Therefore solve for a to get
a = 5
y = 5(x+2)(x-3)
y = 5(x^2-x+6)
y = 5x^2-5x-30