Please solve this..you have to find x

Answer:

he needs to get a 91 to have a mean score of 90

Step-by-step explanation:

add up all the known scores to get 629

let 's' = lowest test score

(629 + s) ÷ 8 = 90   [we divide by 8 because there are 7 known and 1 unknown score)

cross-multiply to get:

629 + s = 720

s = 720-629

s = 91

Answer:

$1225.39

Step-by-step explanation:

Answer:

number 2

Step-by-step explanation:

2x2=4

2x-3=-6

4-6=-2

2x2=4

-2x3=-6

4-6=-2

Answer:

The two values of X that delineate the "82% middle pack" of this random variable are 9480 and 27520.

0.4017 = 40.17% probability that the sample average that you calculated will lie between 1,702 and 1,948.

Step-by-step explanation:

To solve the first question, we use the normal distribution, while for the second quetion, it is used with 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 establishes 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.

First question:

Mean of 18,500:

This means that [tex]\mu = 18500[/tex]

You are told that P(X ≥ 15,000) = 0.6981.

This means that when [tex]X = 15000[/tex], Z has a o-value of 1 - 0.6981 = 0.3019, which means that when [tex]X = 15000, Z = -0.52[/tex]. We use this to find [tex]\sigma[/tex]. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-0.52 = \frac{15000 - 18500}{\sigma}[/tex]

[tex]0.52\sigma = 3500[/tex]

[tex]\sigma = \frac{3500}{0.52}[/tex]

[tex]\sigma = 6731[/tex]

What are the two values of X that delineate the "82% middle pack" of this random variable?

Between the 50 - (82/2) = 9th percentile and the 50 + (82/2) = 91st percentile.

9th percentile:

X when Z has a p-value of 0.09, so X when Z = -1.34.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]-1.34 = \frac{X - 18500}{6731}[/tex]

[tex]X - 18500 = -1.34*6731[/tex]

[tex]X = 9480[/tex]

91st percentile:

X when Z has a p-value of 0.91, so X when Z = 1.34.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.34 = \frac{X - 18500}{6731}[/tex]

[tex]X - 18500 = 1.34*6731[/tex]

[tex]X = 27520[/tex]

The two values of X that delineate the "82% middle pack" of this random variable are 9480 and 27520.

Question 2:

A random variable has a population mean equal to 1,973 and population variance equal to 892,021.

This means that [tex]\mu = 1973, \sigma = \sqrt{892021} = 944.5[/tex]

Sample of 79:

This means that [tex]n = 79, s = \frac{944.5}{\sqrt{79}}[/tex]

What is the probability that the sample average that you calculated will lie between 1,702 and 1,948?

This is the p-value of Z when X = 1948 subtracted by the p-value of Z when X = 1702. So

X = 1948

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{1948 - 1973}{\frac{944.5}{\sqrt{79}}}[/tex]

[tex]Z = -0.235[/tex]

[tex]Z = -0.235[/tex] has a p-value of 0.4071

X = 1702

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{1702 - 1973}{\frac{944.5}{\sqrt{79}}}[/tex]

[tex]Z = -2.55[/tex]

[tex]Z = -2.55[/tex] has a p-value of 0.0054

0.4071 - 0.0054 = 0.4017

0.4017 = 40.17% probability that the sample average that you calculated will lie between 1,702 and 1,948.

Answer:

Mean

Step-by-step explanation:

Mean

less precisely called the average

Answer:

A

Step-by-step explanation:

180-133= 47

180-142= 38

47+38= 85

180-85= 95

If the inside of n is 95, n has to be  85

Answer:

Your welcome! :)

Step-by-step explanation:

To find the inverse of a function, we use the following steps:

1. Replace f(x) with y.

2. Interchange x and y.

3. Solve for y.

4. Replace y with f -1 (x).

Answer:

No solution is posible from the information provided

Step-by-step explanation:

Answer:

1. B

2. C

3. 8, 36

Answer:

Step-by-step explanation:

Hope this helps u !!!

Answer:

[tex]E(10x + 3y) =106[/tex]

Step-by-step explanation:

Given

[tex]E(x) =10[/tex]

[tex]Var(x) = 100[/tex]

[tex]E(y) =2[/tex]

[tex]Var(y) = 16[/tex]

Required

[tex]E(10x + 3y)[/tex]

To do this, we make use of the following equation

[tex]E(ax + by) =aE(x) + bE(y)[/tex]

So, we have:

[tex]E(10x + 3y) =10 * E(x) + 3 *E(y)[/tex]

[tex]E(10x + 3y) =10 * 10 + 3 *2[/tex]

[tex]E(10x + 3y) =100 + 6[/tex]

[tex]E(10x + 3y) =106[/tex]

Answer:

64

Step-by-step explanation:

Half (50%) of 64 would be 32

Answer:

64

Step-by-step explanation:

let the number be x

according to the question ,

50 % of x = 32

50/100 * x = 32

50x = 32 *100

x = 3200/50

x = 64

therefore a number is 64

Step-by-step explanation:

[tex] \frac{x + 4}{3 {x}^{2} - 12x - 96} = \frac{x + 4}{3( {x}^{2} - 4x - 32) } = \frac{x + 4}{3(x - 8)(x + 4)} [/tex]

[tex] = \frac{1}{3(x - 8)} = \frac{1}{3x - 24} [/tex]

Answer:

D is the answer

Step-by-step explanation:

Answer:

23 1/4

Step-by-step explanation:

3/6 ^ 2 = 1/4

7 * 4 = 28

28 + 1/4 = 113/4

113/4 - 5 = 93/4

93/4 = 23 1/4

Step-by-step explanation:

the answer is in the above image

Answer:

A = 190 inches^2

Step-by-step explanation:

The total area would be area for a rectangle + half the area of a circle:

Area for a rectangle:

A = l x w

A = 12 x 15

A = 180 [tex]inches^{2}[/tex]

Area for half of the circle:

A = [tex]\frac{\pi r^{2} }{2}[/tex]

[tex]A = \frac{\pi 2.5^{2} }{2} \\\\= \frac{19.63}{2} \\\\= 9.8 inches^{2}[/tex]

Total area: Rectangle area + half of the circle area

= 180 + 9.8 = 189.8 = 190 inches^2

Step-by-step explanation:

Find the rectangle area first by using the formula A=length * width then find the semicircle area by using the formula A=pi*r²/2

Answer:

14 : 12 , 21 : 18 and 28 : 24 .

Step-by-step explanation:

Answer:

14 : 12 , 21 : 18 and 28 : 24 .

Step-by-step explanation:

Therefore, 14 : 12 , 21 : 18 and 28 : 24

52 Step-by-step explanation:

Answer:

hey. your questions is not complete. pls add an attachment of the graph to your question

Answer:

[tex]-\frac{1}{5}[/tex]

Step-by-step explanation:

To find the slope, the formula is [tex]\frac{y2-y1}{x2-x1}[/tex]

[tex]\frac{1-2}{3-(-2)}=-\frac{1}{5}[/tex]

Hope this helps

Answer:

10 oz: 7

14 oz: 8

20 oz: 6

Answer:

Kyle filled  4 servings of 10oz   16 servings of 14 oz  9 servings of 20 oz

Step-by-step explanation:

10oz  95c = x

14oz 1.15c = y

20oz 1.50c = z

444 given divided by 29 cups

= 444/29 = 15.3103448 average cup weight so the higher size were used more.  

9 servings of 20 oz cups = 180 = cost check at 1.50 x 9 = $13.50

16 servings of 14 oz cups = 224 = cost check at 16 x 1.15 = $18.40

4 servings of 10 oz cups = 40 = cost check at 4 x 0.95 = $3.80

Where given collection total said to be $35.90 we total 13.5+18.4+3.8 = 35.7 so we are 0.20 out and can try again.

OR just submit this.  4 servings of 10oz   16 servings of 14 oz  9 servings of 20 oz

Answer:

YES

Step-by-step explanation:

PRIME NUMBER BETWEEN 10 & 20 ARE 11,13,17,19-four

Step-by-step explanation:

it has no factor excluding 1 and itself

Answer:

p=35

Step-by-step explanation:

2p+5+3p =180 degree (being linear pair)

5p+5=180

5p=180-5

p=175/5

p=35

A linear pair is a pair of adjacent angles formed when two lines intersect.

Answer: (-2x-10y)-(-4x-3y)

-2x-10y-(-4x-3y)

-2x-10y+4x+3y

-2x+4x-10y+3y

-2x+4x-10y+3

Answer =2x-7y

Step-by-step explanation:

Answer:

1. x = 126

angle POS = 33

2. x = 31

angle MOL = 118

Step-by-step explanation:

for question one, 147 degrees equals x + 21

so x = 126

147 plus 147 equals 294

360-294 equals 66

66/2 equals angle POS

angle POS = 33

for question 2, 62 degrees equals 2x

62 divided by 2 is 31

x = 31

62 + 62 = 124

360-124 = 236

236/2 = 118

angle MOL = 118

Answer:76

Step-by-step explanation:

67

Answer:

Amanda can fill 37.5 cups

Step-by-step explanation:

Answer:

12 2/3

Step-by-step explanation:

add the integers to get 6+3 + 4 = 13

Now subtract 1/3

13 = 12 + 1 - 1/3

but one is equal to 3/3

12 + 3/3 - 1/3

12 2/3

Answer:

The numbers are 31 and 44.

Step-by-step explanation:

Given that the difference of two numbers is 13, and the sum of two numbers is 75, to determine what these numbers are, the following calculations must be performed:

(75 - 13) / 2 = X

62/2 = X

31 = X

31 + (31 + 13) = X

31 + 44 = X

75 = X

Therefore, the numbers are 31 and 44.

Answer:

The first is negative and the second is also negative. Just took the test and passed.

Step-by-step explanation: Step by Step

Because the variable has an even power, we will see that:

Here we have h(x) = -4x^2 + 11

Notice that the variable is squared, this means that the sign does not matter, the outcome of:

-4x^2 will always be negative. So in both ends (when x tends to infinity and negative infinity), we will have the same end behavior.

When we take that limit, -4x^2 will just tend to negative infinity, then in both cases, the function tends to negative infinity.

So we have:

If you want to learn more about limits, you can read:

https://brainly.com/question/5313449