Suppose that attendance at the concerts by the band "Keane" is a normally distributed random variable X with a mean of 18,500. You are told that P(X ≥ 15,000) = 0.6981. What are the two values of X that delineate the "82% middle pack" of this random variable?

A random variable has a population mean equal to 1,973 and population variance equal to 892,021. Your interest lies in estimating the population mean of this random variable. With that in mind, you take a representative sample of size 79 from the population of the random variable. You then use this sample data to calculate the sample average as an estimate for the population mean.

Required:
Using your knowledge about the central limit theorem (CLT), and assuming that the CLT has already "established itself" / "kicked in" when the sample size is 79, what is the probability that the sample average that you calculated will lie between 1,702 and 1,948?

Answers

Answer 1

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.


Related Questions

Help will give brailiest to first answer

Answers

question isn't loading

Step-by-step explanation:

Answer:

i think it is b but don't take my word

Step-by-step explanation:

Consider the following hypothesis test. : : The following results are for two independent samples taken from two populations. Excel File: data10-03.xlsx Enter negative values as negative numbers. a. What is the value of the test statistic? (to 2 decimals) b. What is the -value? (to 4 decimals) c. With , what is your hypothesis testing conclusion? - Select your answer -

Answers

Answer:

[tex]z = -1.53[/tex] --- test statistic

[tex]p = 0.1260[/tex] --- p value

Conclusion: Fail to reject the null hypothesis.

Step-by-step explanation:

Given

[tex]n_1 = 80[/tex]     [tex]\bar x_1= 104[/tex]   [tex]\sigma_1 = 8.4[/tex]

[tex]n_2 = 70[/tex]    [tex]\bar x_2 = 106[/tex]    [tex]\sigma_2 = 7.6[/tex]

[tex]H_o: \mu_1 - \mu_2 = 0[/tex] --- Null hypothesis

[tex]H_a: \mu_1 - \mu_2 \ne 0[/tex] ---- Alternate hypothesis

[tex]\alpha = 0.05[/tex]

Solving (a): The test statistic

This is calculated as:

[tex]z = \frac{\bar x_1 - \bar x_2}{\sqrt{\frac{\sigma_1^2}{n_1} + \frac{\sigma_2^2}{n_2} }}[/tex]

So, we have:

[tex]z = \frac{104 - 106}{\sqrt{\frac{8.4^2}{80} + \frac{7.6^2}{70} }}[/tex]

[tex]z = \frac{104 - 106}{\sqrt{\frac{70.56}{80} + \frac{57.76}{70}}}[/tex]

[tex]z = \frac{-2}{\sqrt{0.8820 + 0.8251}}[/tex]

[tex]z = \frac{-2}{\sqrt{1.7071}}[/tex]

[tex]z = \frac{-2}{1.3066}[/tex]

[tex]z = -1.53[/tex]

Solving (b): The p value

This is calculated as:

[tex]p = 2 * P(Z < z)[/tex]

So, we have:

[tex]p = 2 * P(Z < -1.53)[/tex]

Look up the z probability in the z score table. So, the expression becomes

[tex]p = 2 * 0.0630[/tex]

[tex]p = 0.1260[/tex]

Solving (c): With [tex]\alpha = 0.05[/tex], what is the conclusion based on the p value

We have:

[tex]\alpha = 0.05[/tex]

In (b), we have:

[tex]p = 0.1260[/tex]

By comparison:

[tex]p > \alpha[/tex]

i.e.

[tex]0.1260 > 0.05[/tex]

So, we fail to reject the null hypothesis.

3
What is
4
of 100 km?
0,75-100

Answers

Answer:

75 km.

Step-by-step explanation:

Fractions of a number

To get the fraction of a number, we multiply that number by the given fraction.

For example two-thirds of 60 is 2/3 × 60 = 2 × 20 = 40 and one-fifth of 100 is 1/5 × 100 = 100/5 = 20

Now, we are supposed to find a fraction of 100 km. Assume its three-quarters.

So, three-quarters of 100 km is 3/4 × 100 km = 3 × 100 km/4 = 3 × 25 km = 75 km

So, three-quarters of 100 km is 75 km.

A manufacturer knows that their items have a lengths that are skewed right, with a mean of 10 inches, and standard deviation of 1.6 inches. If 39 items are chosen at random, what is the probability that their mean length is greater than 10.5 inches

Answers

Solution :

Given :

Mean, μ = 10 inches

Standard deviation, σ = 1.6 inches

Sample size is n = 39

Therefore,

[tex]$\mu_{\overline x}=\mu = 10$[/tex]

[tex]$\sigma_{\overline x}=\frac{\sigma}{\sqrt n } = \frac{1.6}{\sqrt{39}}$[/tex]

               = 0.25

[tex]$P (\overline X > 10.5 ) = P\left( \frac{\overline X - \mu_{\overline x}}{\sigma_{\overline x}} > \frac{10.5 - 10}{0.25} \right)$[/tex]

                      = P( Z >2)

                       = 1 - P(Z < 2)

                       = 1 - 0.97225 (from standard normal table)

                       = 0.0277

                       

Suppose, as a rough estimate, we say that there are 20 distinct geons used for object recognition; and each geon can come in 5 classifiable qualitative sizes (tiny, small, moderate, large, huge); and a pair of geons can be placed in 10 distinct qualitative relations (geon A on top of geon B; geon A to upper left of geon B; geon A to the left of geon B; and so forth).How many distinct two-geon objects do we have in the space described above?

Answers

Answer:

49500

Step-by-step explanation:

According to the Question,

Given That, Suppose, as a rough estimate, we say that there are 20 distinct geons used for object recognition, and each geon can come in 5 classifiable qualitative sizes (tiny, small, moderate, large, huge). and a pair of geons can be placed in 10 distinct qualitative relations.

We have, District geons = 20 , District Size = 5

So, The Number Of Ways A geon can be selected 20 x 5 = 100

Now, We choose 2 geons From 100 Geons and arrange them in 10 district relations.

So, The number of district two-geon object

= [tex]\left[\begin{array}{ccc}100\\2\end{array}\right] * 10[/tex]

= (100 × 99)/2 × 10

= 49.5×100×10   ⇒ 49500

Suppose you pay $3.00 to roll a fair die with the understanding that you will get back $5 (and your wager) for rolling a 5 or a 2, nothing otherwise. What are your expected net winnings, to the nearest cent?

Answers

Since one dice has 6 numbers
You would have a 2/6 chance or 1/3
You paid $3 so if you rolled both number you would make $10. Then you would have to subtract the cost of $3 from that. So you could win $7. Not sure if you were using on one or 2 dice to roll. You would just count all the numbers on both dice 12. Then you would have a 4 in 12 chance. 4/12 or 1/3 chance.

if sec theta = - √30 / 3, find cos theta.
if sin(-theta) = -0.97, find cos (π/2 - theta).

Answers

Step-by-step explanation:

[tex] \cos \theta = \frac{1}{ \sec\theta } = - \frac{3}{ \sqrt{30} } = - \frac{3 \sqrt{30} }{30} = - \frac{ \sqrt{30} }{10} [/tex]

[tex] \cos( \frac{\pi}{2} - \theta )= \cos \frac{\pi}{2} \cos \theta + \sin \frac{\pi}{2} \sin \theta [/tex]

Note that

[tex] \sin( - \theta) = - \sin \theta[/tex]

[tex] \cos \frac{\pi}{2} = 0 \: \: \: \: \: \sin \frac{\pi}{2} = 1[/tex]

Therefore,

[tex] \cos( \frac{\pi}{2} - \theta ) = 0.97[/tex]

Pythagorean triples are super important to know. If the hypotenuse of a triangle is 15, what are its legs ( hint - use the three, four, five triple)

Answers

Answer:

9, 12

Step-by-step explanation:

Just multiply the 3,4,5 triple by 3 and u get 9, 12, 15

When g(x) = 3x, what is g(5)?

Answers

Answer:

g(5) = 15

Explanation:

If the x in g(x) is 5 then the x beside 3 would also be 5.

g(5) = 3(5)

g(5) = 15

Hope this helps, good luck!

Answer:

g(5)= 15

Step-by-step explanation:

g(x) = 3x and in this situation x =5 (  g(5)  )

so substitute x for 5 in the original equation:

g(x) = 3x --> g(5) = 3(5)

which gives you 15. Hope this helps!

f(x) = 3x + 10
х
f(x)
-3
-2
-1
-4

Answers

The answer is 89 you missed a step

I need help please anyone

Answers

Answer:

base: 3units

height: 5units

Area:15units square

Step-by-step explanation:

you can count the squares in the figure to know the base and hight.

Area of parallelogram= base x height= 3x5= 15 units square.

please give me brainliest, thanks!

Solve the following system. If the​ system's equations are dependent or if there is no​ solution, state this.
12a+35b= 19
24a+8c= 1
28b+8c= 5
A) There is one solution. The solution is (__,__,__)
B) The system is dependent
C) There is no solution

Answers

Answer:

the answer is c .no solution

At Misu's Ice Cream Parlor, their famous 4-layer ice cream cake consists of four layers of ice
cream alternating with layers of cake. If there are 8 flavors of ice cream, and we count
different cakes based on the order of ice cream layers from top to bottom:
a) how many different cakes can be made if flavors can be repeated?

Answers

Answer:

4096 different cakes can be made if flavors can be repeated.

Step-by-step explanation:

Since at Misu's Ice Cream Parlor, their famous 4-layer ice cream cake consists of four layers of ice cream alternating with layers of cake, if there are 8 flavors of ice cream, and we count different cakes based on the order of ice cream Layers from top to bottom, to determine how many different cakes can be made if flavors can be repeated, the following calculation must be performed:

8 x 8 x 8 x 8 = X

64 x 64 = X

4.096 = X

Therefore, 4096 different cakes can be made if flavors can be repeated.

3. Two dice are rolled. What’s the conditional probability that both dice are 5’s if it’s known that the sum of points is divisible by 5?

Answers

Answer:

[tex]Pr =\frac{1}{3}[/tex]

Step-by-step explanation:

Given

[tex]S = \{(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)[/tex]

[tex](3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)[/tex]

[tex](5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)\}[/tex] --- sample space

First, list out all outcomes whose sum is divisible by 5

[tex]A = \{(4,6), (5,5),(6,4)\}[/tex]

So, we have:

[tex]n(A) = 3[/tex]

Next, list out all outcomes that has an outcome of 5 in both rolls

[tex]B = \{(5,5)\}[/tex]

[tex]n(B) =1[/tex]

The required conditional probability is:

[tex]Pr =\frac{n(B)}{n(A)}[/tex]

[tex]Pr =\frac{1}{3}[/tex]

2. The cost of oranges varies directly with the total mass bought. 2 kg of oranges costs $4.50. Describe the relationship between cost and mass in words. You may want to calculate a unit rate first.​

Answers

Answer:

The relationship between the cost/mass is $2.25/kg.

Step-by-step explanation:

You first need to divide $4.50 / 2, to know what a single kilogram mass costs.

$4.50 / 2 = $2.25

Now that you have this unit rate $2.25, You can multiply/add it.

$4.50 + $2.25 is $6.75, + another $2.25 = $9.00, and so on.

solve for this square.

Answers

Answer:

a2

b4

c16 brainliest plzz

Answer:

a) SV = 2

The line that is SV actually is not the full slash. It is halfway, and we know that half of four would be two.

b) RT = 4

This time RT is a full line going all the way down. So it would be 4.

c) p = a + b + c

The lengths are all the same because we calculated in the first question that two is half of four. So the base, height, and hypotenuse are the same, 2.

2 + 2 + 2 = 6

So the perimeter of the triangle RVS is 6.

What is the solution set for the quadratic inequality x2 – 5 ≤ 0?

Answers

Answer: -4...?

Step-by-step explanation:

for the function x^2+8x+7
evaluate f(4)

Answers

Answer:

I think you would have to plug in 4 as X so it would be 4^2 +8(4)+ 7

that would be 16+ 32 +7 and that would equal 55

Find an equation for the line that passes through the points (-2,-6) and (6,4).

Answers

Step-by-step explanation:

Line P passes through POINTS (-2,6) and (6,4). Using y=mx + b where m is the SLOPE(rise divided by the run), and b is the Y-INTERCEPT. Pick the POINT (6,4) and plug into the Y-INTERCEPT EQUATION above to determine the Y-INTERCEPT

i need help finding m<1 please :)

Answers

Answer

c,116°

Step-by-step explanation:

i don't know how to draw a diagram?

Join ends of chord with the center making angles ∠2,∠3 and angle at the center.

angle at the center=128°

∠1=∠2+90°

∠2=∠3

∠2+∠3+128=180

∠2+∠2+128=180

2∠2=180-128=52

∠2=52/2=26

∠1=26+90=116°

sorry i can't explain properly without picure.

Which equation represents a circle with a center at (–3, –5) and a radius of 6 units?

Answers

Answer:

Step-by-step explanation:

The general equation of the circle is:

(x-h)²+(y-k)²=r²

(h, k)=(-3,-5)  are the coordinates of the center of the circle.

r=6  is the radius

The equation of the circle is:

(x+3)²+(y+5)² = 36

Kayla wants to fence in a rectangular dog pen that is 30 ft by 40 ft How would you use wha
you know about geometry to help her ensure that she has truly built a rectangular pen?

Answers

Answer:

Kindly check explanation

Step-by-step explanation:

Given the dimension of the dog pen = 30 ft by 40 ft.

Using the knowledge of geometry, that know that a rectangle has been built, the area of the pen should be :

Area of rectangle = Length * width

Area = 40 * 30

Area = 1200 ft²

Perimeter of rectangle = 2(Length + width)

Perimeter = 2(40 + 30)

Perimeter = 2(70)

Perimeter = 140 feets

Hence, area of the pen should be 1200 ft² and its perimeter or fencing should measure 140 feets

Can someone help me with this question please..

Answers

Answer:

The ordered pair would be (2,3)

2 in the first Box

3 in the second

Your cell phone plan costs 55 dollars a month, plus 35 cents per minute. Write an equation to represent the monthly bill of the cell phone plan.

Answers

Answer: Umm lemme try this

Step-by-step explanation:

55+35=x

Alex wants to arrange chairs in such a way that the number of chairs in a row is equal to the number of columns. He has ordered 5100 tables.
a)How many more tables needed to arrange in such a way that he planned? Justify your answer
2)How many chairs can he remove to arrange in a way that he wants? Justify your answer.

Answers

Answer:

84

59

Step-by-step explanation:

In other to have the same number of chayes in both rows and columns ;

If the Number of chairs per row = x ; then number of chairs per column = x

Then the total number of chairs needed = x * x = x²

Hence, if there are 5100 chairs ;

Number of chairs needed more ;

Take the square root of 5100 ;the round to the next whole number :

B.) For number of chairs to be removed ;

Take the square root of 5100 and round down to the whole number.

Hence,

A.) = √5100 = 71.414 = 72

72² - 5100 = 84

B.) 5100 = 71.414 = 71

5100 - 71² =

What is the value of the following function when x = 0?
y
5
(x)
4
3
2
1
V 2
-54 -3
3
4
х
5

Answers

Answer:

y=-2 when x=0

Step-by-step explanation:

The value of the function f(x), When x = 0 is y = - 2.

What is a polynomial?

A polynomial is an algebraic expression.

A polynomial of degree n in variable x can be written as,

a₀xⁿ + a₁xⁿ⁻¹ + a₂xⁿ⁻² +...+ aₙ.

What is a graph?

The set of ordered pairings (x, y) where f(x) = y makes up the graph of a function.

These pairs are Cartesian coordinates of points in two-dimensional space and so constitute a subset of this plane in the general case when f(x) are real values.

From the graph of the function, it intersects the x-axis at two distinct places

so it is a polynomial of degree two.

Let the given function be f(x).

By observing the graph of the function f(x), When x = 0, f(x) = - 2.

Or y = - 2.

learn more about polynomials here :

https://brainly.com/question/11536910

#SPJ7

6(x + 2) in the simplest form

Answers

Using the Distributive Property we can put this in its simplest form.

6(x+2)

(6)(x)+(6)(2)

6x+12

Answer:

6x + 12

Step-by-step explanation:

Use the distributive property to multiply the 6 to the x and 2 to get 6x + 12.

2(x+3)=x-4
please help me <3

Answers

2(x + 3) = x - 4

distribute

2x + 6 = x - 4

either subtract 6 from both sides or add 4. i will be subtracting 6.

2x = x - 10

subtract x from both sides

x = -10

please help me find the area

Answers

Answer:

320 square feet.

Step-by-step explanation:

For the moment, let's put the square back in place. That would make the length 16 + 8 = 24 and the width 16.

L = 24

W = 16

Area = L * W

Area = 24 * 16

Area = 384

Now the next step is to take out the square. It is 8 * 8 = 64

The area of the figure = 384 - 64 = 320 square feet, and that's the answer.

Answer:

320 in^2

Step-by-step explanation:

we need to find the area of this figure

Firstly divide above picture in two parts

1st figure = (16*16)in.

2nd figure = (8*8)in.

Area of 1st figure = 16*16 = 256 in^2

Area of 2nd figure = 8*8 = 64 in^2

Area of whole figure = ( 256 + 64 )in^2

= 320 in^2

does anyone know the answer to this question ​

Answers

$265.32

r = R/100
r = 4/100
r = 0.04 rate per year,
A = P(1 + r/n)nt
A = 1,000.00(1 + 0.04/1)(1)(6)
A = 1,000.00(1 + 0.04)(6)
A = $1,265.32
1,265.32-1,000=265.32
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