Suppose Hailey has taken four exams and made 86, 94, 76, and 81. If each exam counts equally, what does Hailey need to make on her fifth test to have an overall average of 85?
Answer:
She has to get a score of 88 on that test
Step-by-step explanation:
Take the average of the other grades, and that gives you 84.25. So she has to think about what rating she gives it is 85, and the rating is 88.
Hailey needs to score an 88 on the last exam in order to get an average of 85.
The overall average is the mean and the mean is calculated by adding up all the scores and then dividing by the number of exams.
There are 5 exams but only 4 scores. The 5th score will be denoted, "x" and the average we are looking for is 85.
The fifth score should therefore be:
Overall score = Sum of 5 exams / 5
85 = (86 + 94 + 76 + 81 + x) / 5
85 x 5 = 337 + x
425 = 337 + x
x = 425 - 337
= 88
In conclusion, Hailey needs a score of 88 on the fifth exam.
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Help solve the problem pls
Answer:
x = 2
Step-by-step explanation:
Inverse variation between x and y can be represented as:
xy = k
Where k is the constant of proportionality.
If x = 1 when y = 11, the constant of proportionality, k, would be:
1*11 = k
k = 11
To find x when y = 5.5, substitute y = 5.5 and k = 11 into xy = k
Thus:
x*5.5 = 11
Divide both sides by 5.5
x = 11/5.5
x = 2
Please no troll include work
Help !!!! I don’t understand
Answer:
[tex](g\ o\ f)=-20x+10[/tex]
Step-by-step explanation:
One is given the following functions:
f(x) =5x + 2
g(x) = 4x + 2
One is asked to find the following:
[tex](g\ o\ f)(x)[/tex]
One can rewrite this operation as the following:
g(f(x))
In essence, one substitutes in function (g) in place of the parameter (x), and solves to find the new function formed.
[tex]g(f(x))\\\\=g(-5x+2)\\\\=4(-5x+2)+2[/tex]
Simplify, distribute, multiply every term in the parenthesis by the term outside of it, then simplify,
[tex]=-20x+8+2\\\\=-20x+10[/tex]
find the value of x 3,9,10,8,7,x the mean is 7
Una persona compra borregos, cabras y puercos jabalí. Son 100 animales vivos en total y paga $100 mil pesos. Cada borrego costó $500 pesos, tres cabras cuestan $4000 y cada puerco jabalí $3500.
Si denotamos con la variable xel número de borregos comprados por la persona, con y el número de cabras y con z el número de puercos jabalí, escribe las ecuaciones que representan las relaciones entre x,y,zde acuerdo a la información proporcionada.
Answer:
I'm sorry I just need points
Step-by-step explanation:
Inverse Functions
Using a scientific calculator or graphing calculator find the inverse tangent of the ratio. Round to the nearest degree.
1
⁻
1
a. 45°
b. 90°
c. 0°
d. 1°
Please select the best answer from the choices provided
Answer:
A. 45°
Step-by-step explanation:
I calculated it logically
Suppose that there is a school bond referendum in Greensboro, and 73% of voters support it. You randomly ask 20 Greensboro voters whether they support the bond referendum. The standard error of the sample proportion is _____. The probability that 12 or fewer people (out of 20) in your sample support the bond referendum is _____. Group of answer choices 0.0993; 0.6000 0.0993; 0.0951 0.1095; 0.1170 0.1095; 0.8830
Answer:
The standard error of the sample proportion is 0.0993.
The probability that 12 or fewer people (out of 20) in your sample support the bond referendum is 0.0951.
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.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
73% of voters support it.
This means that [tex]p = 0.73[/tex]
Sample of 20 voters
This means that [tex]n = 20[/tex]
Mean and standard deviation:
[tex]\mu = p = 0.73[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.73*0.27}{20}} = 0.0993[/tex]
The standard error of the sample proportion is 0.0993.
The probability that 12 or fewer people (out of 20) in your sample support the bond referendum is
12/20 = 0.6, so this is the p-value of Z when X = 0.6.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{0.6 - 0.73}{0.0993}[/tex]
[tex]Z = -1.31[/tex]
[tex]Z = -1.31[/tex] has a p-value of 0.0951.
So
The probability that 12 or fewer people (out of 20) in your sample support the bond referendum is 0.0951.
The standard error of the sample proportion is 0.0098.
The probability that 12 or fewer people (out of 20) in your sample support the bond referendum is 0.0951
Given that,
Suppose that there is a school bond referendum in Greensboro, and 73% of voters support it.
You randomly ask 20 Greensboro voters whether they support the bond referendum.
We have to determine,
The standard error of the sample proportion is.
The probability that 12 or fewer people (out of 20) in your sample support the bond referendum is .
According to the question,
There is a school bond referendum in Greensboro, and 73% of voters support it.
20 Greensboro voters whether they support the bond referendum.
To find standard deviation of sample proportion.
[tex]standard \ deviation = \sqrt{\dfrac{p(1-p)}{n}}[/tex]
Where, p = 73% = 0.73
And n = 20
Therefore,
[tex]Standard \ deviation = \sqrt{\dfrac{p(1-p)}{n}}\\\\ Standard \ deviation = \sqrt{\dfrac{0.73(1-0.73)}{20}}\\\\Standard \ deviation = \sqrt{\dfrac{0.73\times 0.27}{20}}\\\\Standard \ deviation = \sqrt{\dfrac{0.19}{20}}\\\\Standard \ deviation = 0.0098[/tex]
The standard error of the sample proportion is 0.0098.
The probability that 12 or fewer people (out of 20) in your sample support the bond referendum is,[tex]\dfrac{12}{20 }= 0.6[/tex]
This is the p-value of Z when X = 0.6.
Therefore,
[tex]Z = \dfrac{X-\mu}{\sigma}\\\\Z = \dfrac{0.6-0.73}{0.993}\\\\Z = -1.31\\\\[/tex]
Z = -1.31 has a p-value of 0.0951.
Hence, The probability that 12 or fewer people (out of 20) in your sample support the bond referendum is 0.0951.
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https://brainly.com/question/24248147
if the sum of any two number is 20 and difference is 10 find the numbers
"The sum of two numbers is 20" can be translated mathematically into the equation:
x + y = 20.
"... and their difference is 10" can be translated mathematically as:
x - y = 10
We can now find the two unknown numbers, x and y, because we now have a system of two equations in two unknowns, x and y. We'll use the Addition-Subtraction Method, also know as the Elimination Method, to solve this system of equations for x and y by first eliminating one of the variables, y, by adding the second equation to the first equation to get a third equation in just one unknown, x, as follows:
Adding the two equations will eliminate the variable y:
x + y = 20
x - y = 10
-----------
2x + 0 = 30
2x = 30
(2x)/2 = 30/2
(2/2)x = 15
(1)x = 15
x = 15
Now, substitute x = 15 back into one of the two original equations. Let's use the equation showing the sum of x and y as follows (Note: We could have used the other equation instead):
x + y = 20
15 + y = 20
15 - 15 + y = 20 - 15
0 + y = 5
y = 5
CHECK:
In order for x = 15 and y = 5 to be the solution to our original system of two linear equations in two unknowns, x and y, this pair of numbers must satisfy BOTH equations as follows:
x + y = 20 x - y = 10
15 + 5 = 20 15 - 5 = 10
20 = 20 10 = 10
Therefore, x = 15 and y = 5 is indeed the solution to our original system of two linear equations in two unknowns, x and y, and the product of the two numbers x = 15 and y = 5 is:
xy = 15(5)
xy = 75
The measure of ZA Is 12° greater than the measure of ZB. The two angles are complementary. Find the measure of each angle. . The mZA IS and m/B Is
Answer:
m∡ZA = 51°
m∡ZB = 39°
Step-by-step explanation:
∡ZB = 'b'
∡ZA = '12 + b'
b + 12 + b = 90
2b + 12 = 90
2b = 78
b = 39
12 + 39 = 51
PLEASE I NEED HELP URGENT I Will MARKE YOU BRAIN LIST
Answer:
1. 0
2. a/ a + b
3. a + b/ a - b
Correct answer will be marked brainliest
find the value of x
4x + 2 = 8
Answer: x = 6/4
Step-by-step explanation:
4x + 2 = 8
4x = 6
x = 6/4 or 1 1/2
Hope this helped :)
Answer:
x = 1.5, 1 1/2
Step-by-step explanation:
4x + 2 = 8
4x = 6
4x/4 = 6/4
x = 1.5
1.5 = 1 1/2
Have a nice day! :-)
Math grade 9 ,I need the answer fassstt
Answer:
Step-by-step explanation:
i dont know sorry
Answer:
a) section c
b) at a constant rate
c) below
A. 3m/s^2
B. 0 m/s^2
C. -3m/s^2
D. 1 m/s^2
Step-by-step explanation:
a) This graph models the change in velocity of time. Since when the velocity decreases over time, the acceleration is negative. This relationship is modeled in the interval from the 9th to 11th seconds which is section c.
b) If the graph is flat, it means the car is traveling at the same amount of meters per second. This means the car is traveling at a constant rate during section b.
c) During section A, the velocity in second 0 to second 4 increases by 12m/s. So, the acceleration is 3m/s^2. This is identical to finding the slope.
During section B, the velocity does not change at all, so the acceleration(and slope) is 0 m/s^2
During section C, over 2 seconds, from 9 to 11, the velocity goes from 12 m/s to 6 m/s, which is a change of -6 m/s. Therefore, the acceleration is -3m/s^2
During section D, over a span of 4 seconds(11 - 15), the velocity changes from 6 m/s to 10 m/s. That means a change of 4 m/s and the acceleration would be 1 m/s^2.
It is known that screws produced by a certain company will be defective with probability 0.01, independently of each other. The company sells the screws in packages of 10 and offers a money-back guarantee that at most 1 of 10 screws are defective. That is, the package would have to be replaced if greater or equal to 2 screws are defective. What proportion of packages sold must the company replace
Answer:
The company must replace 0.0042 = 0.42% of packages.
Step-by-step explanation:
For each screw, there are only two possible outcomes. Either it is defective, or it is not. The probability of an screw being defective is independent of any other screw. This means that the binomial probability distribution is used to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
It is known that screws produced by a certain company will be defective with probability 0.01.
This means that [tex]p = 0.01[/tex]
The company sells the screws in packages of 10
This means that [tex]n = 10[/tex]
That is, the package would have to be replaced if greater or equal to 2 screws are defective. What proportion of packages sold must the company replace?
This is:
[tex]P(X \geq 2) = 1 - P(X < 2)[/tex]
In which:
[tex]P(X < 2) = P(X = 0) + P(X = 1)[/tex]
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{10,0}.(0.01)^{0}.(0.99)^{10} = 0.9044[/tex]
[tex]P(X = 1) = C_{10,1}.(0.01)^{1}.(0.99)^{9} = 0.0914[/tex]
[tex]P(X < 2) = P(X = 0) + P(X = 1) = 0.9044 + 0.0414 = 0.9958[/tex]
[tex]P(X \geq 2) = 1 - P(X < 2) = 1 - 0.9958 = 0.0042[/tex]
The company must replace 0.0042 = 0.42% of packages.
Find the measure of the arc or angle indicated. NO LINKS.
9514 1404 393
Answer:
10. A) 120°
11. D) 40°
12. D) 54°
13. A) 101°
Step-by-step explanation:
The applicable rules of angles and arcs are ...
the whole is the sum of the partsarcs of a circle total 360°an inscribed angle intercepts an arc of twice its measure__
10) Angles C and L intercept the same arc (DE) so will have the same measure.
15x = 16x -4
4 = x . . . . . . . . add 4-15x
arc DE = 2(15x) = 30(4) = 120 . . . degrees
__
11) Arc VW is twice the measure of angle X, so ...
9x +8 = 2(5x)
8 = x . . . . . . . . . subtract 9x
∠VXW = 5x = 5(8) = 40 . . . degrees
__
12) Arc EFG is twice the measure of angle W, so ...
70° +FG = 2(88°)
FG = 106° . . . . . . . . . subtract 70°
Arc FGW is twice the measure of angle E, so ...
106° +GW = 2(80°)
GW = 54° . . . . . . . . . . subtract 106°
__
13) Arc ST is twice the measure of angle R. The sum of arcs is 360°.
RS +ST +TR = 360°
119° +2(70°) +TR = 360°
TR = 101° . . . . . . . . subtract 259°
Calculate the radius or diameter in each of the following problems.
1) d = 8.3 mm
Calculate the radius of the circle.
Answer:
4.15
Step-by-step explanation:
the radius is half the diameter so 8.3/2
=4.15mm
Answer:
4.15
Step-by-step explanation:
radius is the half of the diameter so 8.3/2 is 4.15
What is the value of the expression shown? 10 - 16:2
[tex]10 - 16 \div 2[/tex]
The price of a ticket to attend a show is $28.50. In addition to the ticket price, Laurence had to pay a service fee of 10% and a sales tax
of 6%. The service fee and sales tax are each applied to the original price of the ticket
How much did Laurence pay in total?
Enter your answer in the box.
Answer:
HI!!
Step-by-step explanation:
The area of the triangle shown is represented by A=s(s−14)(s−12)(s−6)−−−−−−−−−−−−−−−−−−−−√A=s(s−14)(s−12)(s−6), where s is equal to half the perimeter. What is the height h of the triangle? Round your answer to the nearest hundredth.
Answer:
[tex]h=5.11ft[/tex]
Step-by-step explanation:
[tex]S=12+6+14/2=16[/tex]
[tex]area ~A= \sqrt{s(s-14)(5-12)(5-6)}[/tex]
[tex]area=\sqrt{16(16-14)(16-12)(16-6)}[/tex]
[tex]A=\sqrt{16×2×4×10}[/tex]
[tex]A=35.70[/tex]
[tex]A=1/2× base~×height[/tex]
[tex]35.70=1/2×14×h[/tex]
[tex]h=2×35.75/14[/tex]
[tex]h=5.11ft[/tex]
｡･:*:･ﾟ★,｡･:*:･ﾟ☆
hope it helps...
have a great day!!
What is the perimeter of a square with a side length of 9 meters?
Answer:
36 meters
Step-by-step explanation:
A square has equal side lengths, and a total of 4 sides, so
9 times 4 is equal to 36.
Remember your units!
All else being equal, if you cut the sample size in half, how does this affect the margin of error when using the sample
to make a statistical inference about the mean of the normally distributed population from which it was drawn?
zes
ME=
O The margin of error is multiplied by 0.5
O The margin of error is multiplied by a
O The margin of error is multiplied by 0.5.
O The margin of error is multiplied by 2.
Answer:
The margin of error is multiplied by 4.
Step-by-step explanation:
Margin of error is:
[tex]M = \frac{zs}{\sqrt{n}}[/tex]
In which z is related to the confidence level, s is elated to the standard deviation and n is the sample size.
From this, we have that the standard deviation is inversely proportional to the square root of the sample size.
If you cut the sample size in half:
The margin of error is inversely proportional to the square root of the sample size, so if you cut the sample size by [tex]\frac{1}{2}[/tex], the margin of error will be multiplied by [tex]2^2 = 4[/tex]
So
The margin of error is multiplied by 4.
NEED HELP ASAP! WILL GIVE BRAINLY :)
Answer:
y = x - 3
Step-by-step explanation:
Slope = Rise / run
Slope = 4/4 = 1
y-intercept = -3
y = x - 3
How many times longer I s on be mile that one foot
Answer:
5,280 times
hope this helps
have a good day :)
Step-by-step explanation:
Find the area of the polygon shown. Enter the number into the box.
ft? 1 ft 4 ft 4 ft
Answer:
The area of the trapezium is 18 ft²
Step-by-step explanation:
Given;
Two parallel sides of the polygon as follows;
The first parallel side = 1 ft + 4 ft = 5 ft
The second parallel side = 4 ft
If this polygon is rotated 90 degrees, it forms a trapezium with a height of 4 ft.
The area of a trapezium is calculated as;
[tex]A rea= \frac{1}{2} (sum \ of \ parallel \ sides) \times height\\\\Area = \frac{1}{2} (5 \ + \ 4) \times 4\\\\Area = 18 \ ft^2[/tex]
Therefore, the area of the trapezium is 18 ft²
The segments shown below could form a triangle.
A. True
B. False
Answer:
true
Step-by-step explanation:
The price of a video game was reduced from $60 to $45. By what percentage was the price of
the video game reduced?
F 15%
G 25%
H 75%
4096
Someone please help
Answer:
G. 25%
Step-by-step explanation:
given : The price of a video game was reduced from $60 to $45 .
$60 - $45 = $15
then, the percentage was the price of the video game reduced :-
reduction in price/previous price x 100 = 15/60 x 100 = 25%
the percentage was the price of the video game reduced = 25%
PLEASEEEEEEEEEEEEE HELPPPPPPPPPPPPPPP AM GOING TO FAIL
Answer:
2b + 10
Step-by-step explanation:
How many children would you need to invite to the party for the cost to be the same both places
Answer:
4 children
Step-by-step explanation:
Let the number of children = c.
The cost of the pizza place for c children (without the fee) = 8c
The cost of the pizza place for c children (with the fee) = 8c+30
The cost of the taco place for c children (without the fee) = 12c
The cost of the taco place for c children (with the fee) = 12c+14
To find c when the totals are equal, set 8c+30 equal to 12c+14 and solve:
8c+30=12c+14
8c-12c=14-30
-4c=-16
c=4
Help pls I’ll give extra pointz
Answer:
The answer is (A) decreases
which set of side lengths can form a triangle?
А: 2 cm, 2cm. 6 cm
B:3 cm 6 cm, 9 cm
C:4 cm, 8 cm, 5 cm
D:8 cm, 3 cm, 4 cm
Answer:
C:4 cm, 8 cm, 5 cm
Step-by-step explanation:
sum of length of any two sides of a triangle will be larger than the third side.