Answer:
a) 0.4772 = 47.72% probability that the average is between 1,142 and 1,150.
b) 0.0228 = 2.28% probability that the average is greater than 1,158.
c) 0 = 0% probability that the average is less than 950.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
A certain type of automobile battery is known to last an average of 1,150 days with a standard deviation of 40 days.
This means that [tex]\mu = 1150, \sigma = 40[/tex]
Sample of 100:
This means that [tex]n = 100, s = \frac{40}{\sqrt{100}} = 4[/tex]
(a) The average is between 1,142 and 1,150.
This is the pvalue of Z when X = 1150 subtracted by the pvalue of Z when X = 1142. So
X = 1150
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{1150 - 1150}{4}[/tex]
[tex]Z = 0[/tex]
[tex]Z = 0[/tex] has a pvalue of 0.5
X = 1142
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{1142 - 1150}{4}[/tex]
[tex]Z = -2[/tex]
[tex]Z = -2[/tex] has a pvalue of 0.0228
0.5 - 0.0228 = 0.4772
0.4772 = 47.72% probability that the average is between 1,142 and 1,150.
(b) The average is greater than 1,158.
This is 1 subtracted by the pvalue of Z when X = 1158. So
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{1158 - 1150}{4}[/tex]
[tex]Z = 2[/tex]
[tex]Z = 2[/tex] has a pvalue of 0.9772
1 - 0.9772 = 0.0228
0.0228 = 2.28% probability that the average is greater than 1,158.
(c) The average is less than 950.
This is the pvalue of Z when X = 950. So
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{950 - 1150}{4}[/tex]
[tex]Z = -50[/tex]
[tex]Z = -50[/tex] has a pvalue of 0
0 = 0% probability that the average is less than 950.
Can somebody please help me out please my grads are bad
Enter in the missing numbers to create equivalent ratios. HELPPPPPPPPPPPPPPPPPPPP
What is the value of the expression below when x =6 and y =2? Xy-y^3
What is the volume of a sphere with a radius of 10 inches? Round to the nearest hundredth.
What is the volume of a sphere with a radius of 7 feet? Round to the nearest hundredth.
6
What is the volume of the sphere with a diameter of 18 centimeters? Round to the nearest
hundredth
Answer:
5. 4186.67 in³
6. 1436.03 ft³
7. 3052.08 cm³
Step-by-step explanation:
5. Determination of the volume of the sphere.
Radius (r) = 10 in
Pi (π) = 3.14
Volume (V) =?
V = 4/3πr³
V = 4/3 × 3.14 × 10³
V = 4/3 × 3.14 × 1000
V = 4186.67 in³
6. Determination of the volume of the sphere.
Radius (r) = 7 ft
Pi (π) = 3.14
Volume (V) =?
V = 4/3πr³
V = 4/3 × 3.14 × 7³
V = 4/3 × 3.14 × 343
V = 1436.03 ft³
7. Determination of the volume of the sphere.
We'll begin by calculating the radius. This can be obtained as follow:
Diameter (d) = 18 cm
Radius (r) =?
r = d/2
r = 18/2
r = 9 cm
Finally, we shall determine the volume of the sphere. This can be obtained as follow:
Radius (r) = 9 cm
Pi (π) = 3.14
Volume (V) =?
V = 4/3πr³
V = 4/3 × 3.14 × 9³
V = 4/3 × 3.14 × 729
V = 3052.08 cm³
Which inequality represents all possible solutions of -6n < -12
Answer:
The only solutions would be that the numbers HAVE to be greater than 2
Step-by-step explanation:
-6n < -12
-n < -2
n > 2
HELP PLEASE SOMEONE:(
Answer:
C. 5°F
Step-by-step explanation:
- 5°F + 5°F
0°F
Which expressions correctly represent the area of the triangle XYZ?
Answer:
Options (2) and Option (1)
Step-by-step explanation:
Area of the ΔXYZ = [tex]\frac{1}{2}(\text{Base})(\text{Height})[/tex]
= [tex]\frac{1}{2}(XZ)h[/tex]
= [tex]\frac{1}{2}(18)h[/tex]
By applying sine rule in the ΔYPZ,
sin(38°) = [tex]\frac{\text{Opposite side}}{\text{Hypotenuse}}[/tex]
sin(38°) = [tex]\frac{h}{14}[/tex]
h = 14[sin(38°)]
Therefore, area of the given triangle = [tex]\frac{1}{2}(18)(14)sin(38)[/tex]
By applying sine rule in ΔYPZ,
sin(58°) = [tex]\frac{\text{Opposite side}}{\text{Hypotenuse}}[/tex]
sin(58°) = [tex]\frac{h}{10}[/tex]
h = 10sin(58°)
Area of ΔXYZ = [tex]\frac{1}{2}(18)(10)sin(58)[/tex]
Therefore, Options (2) and Option (1) are the correct options.
Use the completing the square method to transform the equation x^2 + 2x =13 into an equation of the form (x + a)^2 = b where a and b are real numbers. What are the values of a and b?
Answer: part A is 1 and part B is 14
Step-by-step explanation:
Quadratic below
2^2−7−4
Vertex -
Y-Intercept -
X-Intercept -
Answer:
The y-intercept is y = -4.
The x-intercepts are [tex]x = 4[/tex] and [tex]x = -\frac{1}{2}[/tex]
The vertex is [tex](\frac{7}{4},-\frac{81}{8})[/tex]
Step-by-step explanation:
Quadratic equation:
Has the following format:
[tex]y = ax^2 + bx + c[/tex]
The y-intercept is c.
Finding the x-intercepts:
Given a second order polynomial expressed by the following equation:
[tex]ax^{2} + bx + c, a\neq0[/tex].
This polynomial has roots [tex]x_{1}, x_{2}[/tex] such that [tex]ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})[/tex], given by the following formulas:
[tex]x_{1} = \frac{-b + \sqrt{\Delta}}{2*a}[/tex]
[tex]x_{2} = \frac{-b - \sqrt{\Delta}}{2*a}[/tex]
[tex]\Delta = b^{2} - 4ac[/tex]
Vertex:
Suppose we have a quadratic function in the following format:
[tex]f(x) = ax^{2} + bx + c[/tex]
It's vertex is the point [tex](x_{v}, y_{v})[/tex]
In which
[tex]x_{v} = -\frac{b}{2a}[/tex]
[tex]y_{v} = -\frac{\Delta}{4a}[/tex]
Where
[tex]\Delta = b^2-4ac[/tex]
In this question:
The quadratic equation is [tex]2x^2 - 7x - 4[/tex], which has [tex]a = 2, b = -7, c = -4[/tex]. This means that the y-intercept is y = -4.
x-intercepts:
[tex]\Delta = (-7)^2-4(2)(-4) = 81[/tex]
[tex]x_{1} = \frac{-(-7) + \sqrt{81}}{2*2} = 4[/tex]
[tex]x_{2} = \frac{-(-7) - \sqrt{81}}{2*2} = -\frac{1}{2}[/tex]
The x-intercepts are [tex]x = 4[/tex] and [tex]x = -\frac{1}{2}[/tex]
Vertex:
[tex]x_{v} = -\frac{(-7)}{2*2} = \frac{7}{4}[/tex]
[tex]y_{v} = -\frac{81}{4(2)} = -\frac{81}{8}[/tex]
The vertex is [tex](\frac{7}{4},-\frac{81}{8})[/tex]
don’t mind the pencil writing
Answer:
Length = 22 cm
Width = 4 cm
Step-by-step explanation:
Area = 88 cm²
Length = x + 7
Width = x - 11
Area of rectangle = length*width
Therefore:
(x + 7)(x - 11) = 88
x(x - 11) +7(x - 11) = 88
x² - 11x + 7x - 77 = 88
Add like terms
x² - 4x - 77 = 88
x² - 4x - 77 - 88 = 88 - 88
x² - 4x - 165 = 0
Factorize
x² - 15x + 11x - 165 = 0
x(x - 15) +11(x - 15) = 0
(x + 11)(x - 15) = 0
x = -11 or x = 15
Let's use the positive number.
Therefore:
Length = x + 7
Plug in the value of x
Length = 15 + 7 = 22 cm
Width = x - 11 = 15 - 11 = 4 cm
Find the area of rectangle ABCD
Answer: 12
Step-by-step explanation:
You can find the area of a rectangle that forms around it, and then subtract the little extra triangles. You can form a 5 by 5 square around the points. There are 4 extra little triangles. Two of them have a base and height of 2 and 2. Two of them have a base and height of 3 and 3. So you get the total area of those 4 triangles to be: 2+2+4.5+4.5=13. So 25-13=12.
Suppose you roll a 6-sided number cube twice, and each time you
rolled a 4. a) Is the rolling of the number cube twice independent or
dependent events? b) What is the probability of rolling two fours? c)
Explain the difference between independent and dependent events.
If you sleep 6 hrs out of 24 hrs how much percent do you sleep?
Answer:
25%
Step-by-step explanation:
I hope this helps you!!
Answer:
You sleep 25% of the day.
Step-by-step explanation:
First you change the equation into a fraction:
6 hrs out of 24 hrs = 6/24
Then you can simplify this fraction:
6/24 = 1/4
Lastly, convert the fraction to a percent:
1/4 = 25%
Brainliest would be greatly appreciated!!!!
Plz help me well mark brainliest if correct!....
Answer:
C
Step-by-step explanation:
B can immediately be eliminated because it has an area of 14.
A and C have an area of 10.
So add the sides.
C:
4 + 4 + 1 + 1 + 2 + 2 + 1 + 3
= 18
A: 3 + 3 + 2 + 2 + 1 + 1 + 1 + 1 =
10 + 4 =
14
ANSWER ASAP! WILL MARK BRAINLIEST!
Select all the correct answers.
Which two tables represent the same function?
х|у
4|8
6|7
х|у
4|5
6|4
х|у
2|8
8|5
x|y
2|10
6|14
x|y
2|9
8|6
Answer:
The first and last set
y = (-1/2) + 10
Step-by-step explanation:
Two points form a line
The first and last set have a slope of -1/2
and b intercept of 10
х|у
4|8
6|7
y = (-1/2) + 10
and
x|y
2|9
8|6
y = (-1/2) + 10
The requried, tables that represent the same function are tables 1 and 3.
What is function?In mathematics, a function is a relationship between two sets of numbers, known as the domain and range, in which each element in the domain is associated with exactly one element in the range.
Here,
The tables that represent the same function are:
x|y
4|8
6|7
x|y
2|8
8|5
For two tables to represent the same function, they must have the same output for the same input. In the first table, input 4 gives output 8 and input 6 gives output 7. In the second table, input 2 gives output 8 and input 8 gives output 5. Therefore, these two tables represent the same function.
The other tables do not represent the same function, as they have different outputs for the same input values.
Learn more about function here:
brainly.com/question/21145944
#SPJ7
If bob has 10 apples and joe takes 2 how many apples does bob have ?
10-2=8
So,Bob has 8 apples left
Answer:
8 apples
Step-by-step explanation:
10-2=8 apples
How many apples does Bob have ? Bob is left with 8 apples now.
Find lim f(x) as x->2- and lim f(x) as x->2+
Answer:
2x the correct answer okay
someone please help me with this
9514 1404 393
Answer:
x = 39
Step-by-step explanation:
The Pythagorean theorem tells you the sum of the squares of the sides of a right triangle is the square of the hypotenuse.
x² +80² = 89²
x² = 89² -80² = 7921 -6400 = 1521
x = √1521
x = 39
A stores revenue is the function y = 150x where x is the number of items they sell. Its cost function is
y = 7x + 2200 where x is the number of items they sell. How many items do they have to sell to break-
even? Show how to solve this using inverses and not the table on your calculator.
NO LINKS TO FILES OR ANYTHING LIKE THAT.
9514 1404 393
Answer:
about 15 or 16 items
Step-by-step explanation:
The break-even point is where revenue is equal to cost.
150x = 7x +2200
143x = 2200 . . . . . . . subtract 7x
x ≈ 15.38 . . . . . . . . . . divide by 143 (multiply by the inverse of 143)
__
When 15 items are sold, revenue doesn't quite cover costs. Costs still exceed revenue by 55. When 16 items are sold, revenue exceeds costs by 95. (I would call this the break-even point, because I prefer a slight profit over a slight loss.)
What is the relationship between how Jews were portrayed to the public and their persecution during the holocaust?
Hint: Find how they were portrayed to the public by Hitler and then follow that up with How were they persecuted during the Holocaust?
Answer:
Step-by-step explanation:
This is actually in the wrong place. It should probably be in English or History, but I'll answer it anyway.
You need to start by seeing the way they were portrayed in cartoons, in writing (mainly newspapers), on the radio, in speeches and on the streets. Start with the Bible. The Old Testament was about the law mostly and behavior as much as anything. The people who lived and were governed by the OT generally were very pious unless they were rebellious sinners.
The New Testament is a slightly different matter. In most of Europe the peasantry thought the Jews were Christ Killers. That thought was dominent throughout the Middle Ages. It isn't true. Jesus was a Jew, so were the disciples, so were the huge crowds that followed Him to at least hear what he had to say.
It was only the ruling classes (The Pharisees, the Sadducees, and the scribes and teachers), that were not fond of Jesus. But that fact was not emphasized. Out of that picture and the displacement of the Jews after the Temple was destroyed, grew the caricatures of what the Jews were.
Anti Semitism was quite common in Europe. Most people fell for the propaganda that said the Jews were the spawn of the Devil. It became easy to kill those that were felt to be evil.
I urge you to start your own study of what happened. Start with the Inquisition.
Need help ASAP plz !!!!!
Answer:
yep that is correct!
Step-by-step explanation:
Theorem of Pythagoras
hopefully the picture is clear and understandable!
:)
len
2. Demetri wakes up at 9:15. It takes him
35 minutes to fold 4 loads of laundry,
35 minutes to bathe the dog, 45 minutes
to bake brownies, and 1 hour to mow the
lawn. After he finishes all of his chores,
he sits down to rest. What time does
Demetri rest?
Answer:
I think the answer is 11.20 am
help i dont reamember how to do this plz
Given : M, N, O are midpoints of AB, BC, AC Complete the following statements
MNOA is a
Please help!!
find the value of the trig ratio.
So with sine cosine and tangent, try remembering the following:
Sin : Opposite / Hypotenuse
Cos: Adjacent / Hypotenuse
Tan: Opposite / Adjacent
Or just remember "Soh-cah-toa".
Thinking Process:Anyways, with this, its asking for the sine ratio of angle Z. So we need the opposite side length and the hypotenuse side length
For the opposite side length, look to see where the angle is "opening" up towards, like a door that is opening. With this, Angle Z is opening up towards the Side XY, which has a length of 21.
To find the hypotenuse, it is always the largest side length of a right triangle. It is also where the right angle opens up it's "door" up to. This would be Side XZ, which has a length of 29.
Answer:With both of these, back to the ratio formula:
Sin : Opposite / Hypotenuse
To finish the question, simply plug in the values that were found above.
This will give you:
Sin Z : 21 / 29
This will be Choice A.
Long before music was recorded digitally, people listened to music played on phonographs.
An antiques dealer models the value of a vintage phonograph using the function V(t) =
0.04t? - 3t + 395, where V(t) is the value in dollars and t is the number of years since 1925.
The phonograph's value dropped as newer versions were introduced but then rose as it
became an antique.
In what year did the phonograph's value equal the value it had in the year 1925? What was
that value?
Round your answers to the nearest whole number.
The phonograph was worth $
value again in the year
in the year 1925. The phonograph had that same
Answer: 395 and 2000
Step-by-step explanation:
It’s correct that’s all you need to know
Solve x2 – 6x + 9 = 0 by completing the square.
Answer:
11/6
Step-by-step explanation:
See the steps below:)
Determine the volume!
Some one help will give brain
Answer:
what the link? didfbdsfaahsdfhsd
Step-by-step explanation:
Similar Triangles
When are triangles considered similar?
a. corresponding angles are equal AND corresponding sides are proportional
b. corresponding angles are proportional AND corresponding sides are equal
c. corresponding angles are equal OR corresponding sides are proportional
d. corresponding angles are proportional OR corresponding sides are equal
Please select the best answer from the choices provided
Answer:
A. Corresponding angles are equal AND corresponding sides are proportional
Step-by-step explanation:
I calculated it logically
Answer:
A. Corresponding angles are equal AND corresponding sides are proportional