The Office of Student Services at a large western state university maintains information on the study habits of its full-time students. Their studies indicate that the mean amount of time undergraduate students study per week is 20 hours. The hours studied follows the normal distribution with a population standard deviation of six hours. Suppose we select a random sample of 150 current students. What is the probability that the mean of this sample is between 19.25 hours and 21.0 hours

Answers

Answer 1

Answer:

0.8254 = 82.54% probability that the mean of this sample is between 19.25 hours and 21.0 hours

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.

Mean of 20 hours, standard deviation of 6:

This means that [tex]\mu = 20, \sigma = 6[/tex]

Sample of 150:

This means that [tex]n = 150, s = \frac{6}{\sqrt{150}}[/tex]

What is the probability that the mean of this sample is between 19.25 hours and 21.0 hours?

This is the p-value of Z when X = 21 subtracted by the p-value of Z when X = 19.5. So

X = 21

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

By the Central Limit Theorem

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

[tex]Z = \frac{21 - 20}{\frac{6}{\sqrt{150}}}[/tex]

[tex]Z = 2.04[/tex]

[tex]Z = 2.04[/tex] has a p-value of 0.9793

X = 19.5

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

[tex]Z = \frac{19.5 - 20}{\frac{6}{\sqrt{150}}}[/tex]

[tex]Z = -1.02[/tex]

[tex]Z = -1.02[/tex] has a p-value of 0.1539

0.9793 - 0.1539 = 0.8254

0.8254 = 82.54% probability that the mean of this sample is between 19.25 hours and 21.0 hours


Related Questions

ind g(x), where g(x) is the translation 5 units right of f(x) = x.

Write your answer in the form mx + b, where m and b are integers.


A. g(x)= x + 5
B. g(x)= x - 5
C. g(x)= x(5)
D. none of the above

Answers

Answer is D
A is translating up
B is translating down
C is multiplying so no

help please..............

Answers

Answer:

19.4 in.

Step-by-step explanation:

PLEASE HELP 7TH GRADE MATH
BRAINLIEST-SHOWS WORK
PLEASE HELP
ANSWE 1 OR MORE AN WILL MARK BRAINLIEST 1 OR MORE

Answers

Answer:

The volume of the pyramid is 126in^3

Step-by-step explanation:

To find the volume of a pyramid you need to use this formula which is

V=lw·h/3

V=9·6·7/3

V=54·7/3

V=126in^3

Solve (x – 3)^2 = 5
please help ASAP

Answers

Step-by-step explanation:

Step 1: Simplify both sides of the equation.

x^2−6x+9=5

Step 2: Subtract 5 from both sides.

x^2−6x+9−5=5−5

x^2−6x+4=0

Step 3:  a=1, b=-6, c=4

1x^2+−6x+4=0

Step 4: Quadratic formula (a) =1, b=-6, c=4

x= 6±√20 /2

Step 4: Last Step

x=3−√5

Explanation in words:

The first step of solving (x – 3)^2 = 5 is to use the quadratic formula. So the first step is to Simplify both sides of the equation which is the (x−3)^2. Our answer will led up to 5 after that.

Moving on to step 2 we will have to now subtract the 5 from both sides. So 5−5 = 0. So in this step, our answer is now led up to 0.

Now on the step 3 we will now have to use the formula named "quadratic formula". So in this case we will solve this equation with that formula       a=1, b=-6, c=4. At the end our answer will led up to x=3−√5.

Answer:

x=3+√5

x=3−√5

Hope this helps.

Answer:

Step-by-step explanation:

IG you wanted to solve for X ?   there are two answers ofc,  

x= 3-[tex]\sqrt{5}[/tex]

x=3+[tex]\sqrt{5}[/tex]

A professor pays 25 cents for each blackboard error made in lecture to the student who pointsout the error. In a career ofnyears filled with blackboard errors, the total amount in dollarspaid can be approximated by a Gaussian random variableYnwith expected value 40nandand variance 100n. What is the probability that 20exceeds 1000

Answers

Answer:

The correct answer is "0.0000039110".

Step-by-step explanation:

The given values are:

[tex]Y_n\rightarrow N(\mu, \sigma^2)[/tex]

[tex]\mu = 40n[/tex]

[tex]\sigma^2=100n[/tex]

[tex]n=20[/tex]

then,

The required probability will be:

= [tex]P(Y_{20}>1000)[/tex]

= [tex]P(\frac{Y_{20}-\mu}{\sigma} >\frac{1000-40\times 20}{\sqrt{100\times 20} } )[/tex]

= [tex]P(Z>\frac{1000-800}{44.7214} )[/tex]

= [tex]P(Z>\frac{200}{44.7214} )[/tex]

= [tex]P(Z>4.47)[/tex]

By using the table, we get

= [tex]0.0000039110[/tex]

Can someone help me rnnn please??

Answers

Answer:

(-6,2)

Step-by-step explanation:

when it asks for the scale factor all you do is take your coordinates and multiply it by whatever the question gives you. Like in this question you would multiply -3 and 1 by 2 and whatever the number comes out to be then thats your answers.

Sorry if the explanation isnt very good!

An automobile passes a point PP at a speed of 84 mph. At PP it begins to decelerate at a rate proportional to time. If after 6.3 sec the car has slowed to 45 mph, what distance has it traveled in ft

Answers

Answer:

Distance in ft = 597.57 feet

Step-by-step explanation:

As per the

First equation of motion

84 mph = 37.5514 m/s

45 mph = 20.1168 m/s

v-u = a* t

Substituting the given values, we get -

37.5514 m/s - 20.1168 m/s = a * 6.3

a = 2.76 m/s^2

Now as per Newton's third law of motion

v^2-u^2 = 2 *a*S

Substituting the given values, we get -

37.5514^2 - 20.1168^2 = 2 * 2.76 m/s^2 * S

S = 182.142 Meters

Distance in ft = 597.57 feet

Does the equation y = 2(1/2)x represent exponential growth or decay

Answers

Answer:

Growth.

Step-by-step explanation:

y = 2(1/2)x is the same as y = x. as it multiplies and divides x by 2. y = x is exponential growth.

Hope that this helps!

Find the volume of the solid obtained by rotating the region under the graph of the function f(x)=5x−x2 about the x-axis over the interval [0,5].

V=?

Answers

Trade for trade here The Meaning of Freedom in the United States
Between the 1860s and the 1920s
In this essay, you are going to explain how the meaning of freedom changed from the Civil War until the
Roaring Twenties.
Your essay should at least include the following:
• Introductory Paragraph: Briefly state how you think the meaning of freedom changed during this
period.
• Body Paragraph 1: What did freedom mean to the slaves freed after the Civil War? (Unit 1)
• Body Paragraph 2: What did freedom mean to Native Americans at the end of the 19th century?
(Unit 2)
• Body Paragraph 3: What did freedom mean to women in the Suffrage Movement? (Unit 4)
• Additional Paragraphs: Add other historical examples. Optional
. Concluding Paragraph: Summarize your argument. Was there an expansion in freedom during
this period? What groups gained more freedom? What obstacles remained?
Provide a title to your essay and then write at least five paragraphs.
V= help me...

what is the volume of a rectangle prism that is 1 1/2 inches by 2 1/4 inches by 4 inches?

Answers

Answer:

13.5 inches

Step-by-step explanation:

11.5 x 2.25 x 4

I could be wrong

Answer:

13.5 inches is correct :)

Find what value of x makes the equation true

Answers

[tex]\sf\purple{The\:value\:of\:x\:is\:10.4.}[/tex]✅

Step-by-step explanation:

[tex] \frac{(10x - 4)}{5} = 20 \\ ✒ \: 10x - 4 = 20 \times 5 \\ ✒ \: 10x = 100 + 4 \\ ✒10x = 104 \\ ✒ \: x = \frac{104}{10} \\ ✒ \: x = 10.4[/tex]

[tex]\sf\red{Therefore,\:the\:value\:of\:x\:is\:10.4.}[/tex]

To verify:-

[tex] \frac{(10x - 4)}{5} = 20 \\ ✒ \: \frac{10 \times 10.4 - 4}{5} = 20 \\ ✒ \: \frac{104 - 4}{5} = 20 \\ ✒ \: \frac{100}{5} = 20 \\ ✒ \: 20 = 20 \\ ✒ \: L.H.S.=R. H. S[/tex]

Hence verified.

[tex]\circ \: \: { \underline{ \boxed{ \sf{ \color{green}{Happy\:learning.}}}}}∘[/tex]

Consider the following hypothesis test: H 0: 50 H a: > 50 A sample of 50 is used and the population standard deviation is 6. Use the critical value approach to state your conclusion for each of the following sample results. Use = .05. a. With = 52.5, what is the value of the test statistic (to 2 decimals)? 2.42 Can it be concluded that the population mean is greater than 50? Yes b. With = 51, what is the value of the test statistic (to 2 decimals)? .97 Can it be concluded that the population mean is greater than 50? No c. With = 51.8, what is the value of the test statistic (to 2 decimals)? 1.65 Can it be concluded that the population mean is greater than 50? Yes

Answers

Answer:

Step-by-step explanation:

From the question we are told that:

Null Hypothesis [tex]H_0: 50[/tex]

Alternative Hypothesis [tex]H_a: > 50[/tex]

Sample size [tex]n=50[/tex]

standard deviation[tex]\sigma=6[/tex]

Significance level [tex]\alpha=0.05[/tex]

a)

Sample mean [tex]\=x=52.5[/tex]

Generally the equation for Test statistics is mathematically given by

[tex]t=\frac{\=x-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex]

[tex]t=\frac{52.5-50}{\frac{6}{\sqrt{50} } }[/tex]

[tex]t=2.95[/tex]

Therefore from table

[tex]Critical\ value=1.645[/tex]

We conclude The value of test statistics is greater than critical value.

Therefore we Reject the Null hypothesis [tex]H_0[/tex]

b)

Sample mean [tex]\=x=51[/tex]

Generally the equation for Test statistics is mathematically given by

[tex]t=\frac{\=x-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex]

[tex]t=\frac{51-50}{\frac{6}{\sqrt{50} } }[/tex]

[tex]t=1.18[/tex]

Therefore from table

[tex]Critical\ value=1.645[/tex]

We conclude,The value of test statistics is less than critical value.

Therefore we Fail to Reject the Null hypothesis [tex]H_0[/tex]

c)

Sample mean [tex]\=x=51[/tex]

Generally the equation for Test statistics is mathematically given by

[tex]t=\frac{\=x-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex]

[tex]t=\frac{51.8-50}{\frac{6}{\sqrt{50} } }[/tex]

[tex]t=2.12[/tex]

Therefore from table

[tex]Critical\ value=1.645[/tex]

We conclude The value of test statistics is greater than critical value.

Therefore we Fail to Reject the Null hypothesis [tex]H_0[/tex]

I really need help on this any help ?!?!? Extra points!?

Answers

Answer:

circumference = 2πr

diameter = 3ft, so radius =3/2 =1.5

                       =2π ×1.5=3π= 9.42ft

Answer:

here diameter =3 ft

radius=diameter/2

=3/2

=1.5 ft

now use formula 2 pie r where pie =3.14

=2*3.14*1.5 ft

=9.42 ft

Step-by-step explanation:

Hope this helps u!!

travis buys a new baseball cap for $25. the tax rate is 8%.how much money does travis spend in all on the cap?

Answers

Answer: $2

Step-by-step explanation:

3. Find mZS.
Q= 5x + 2)
P= 10x - 3)
(7x - 11)=ºR
(13x - 31)º=S
(8x - 19)=T

Answers

Answer:

∠S = 151

Step-by-step explanation:

The figure shown is a pentagon

The angles in a pentagon add up to equal 540

Thus, ∠Q + ∠P + ∠T + ∠S + ∠R = 540

Or 10x - 3 + 5x + 2 + 7x - 11  + 13x - 31 + 8x - 19 = 540

This is the equation we will use to solve for x

Step 1 combine like terms

10x = 5x + 7x + 13x + 8x = 43x

-3 + 2 - 11 - 31 - 19 = -62

We now have 540 = 43x - 62

Step 2 add 62 to each side

-62 + 62 cancels out

540 + 62 = 602

we now have 602 = 43x

Step 3 divide each side by 43

43x / 43 = x

602 / 43 = 14

we're left with x = 14

Finally we plug in 14 for x in the given expression for ∠S

∠S = 13x - 31

* substitute 14 for x *

∠S = 13 ( 14 ) - 31

∠S = 13 * 14 = 182

182 - 21 = 151

Thus, ∠S = 151

The measure of ∠S is equal to 151°.

What is a shape?

In mathematics, shapes define the perimeters or contours of an object. The forms can be categorized into numerous groups according to their individual traits. A border or outline made up of points, lines, curves, etc. frequently surrounds the forms.

As per the given data:

We are given the diagram of a shape and all its internal angles.

As the given shape is having 5 sides, it will be a pentagon.

The sum of all internal angles in a pentagon is equal to 540°.

∴ ∠P + ∠Q + ∠R + ∠S + ∠T = 540°

⇒ 10x - 3 + 5x + 2 + 7x - 11 + 13x - 31 + 8x - 19 = 540

= 43x - 62 = 540

= 43x = 602

x = 14

To find the measure of ∠S.

∠S = 13x - 31

∠S = 13(14) - 31

∠S = 151°

The measure of ∠S is equal to 151°.

To learn more about shape, click:

brainly.com/question/28978432

#SPJ2

L.C.M of 4 and multiples of 4 and 8

Answers

L.C.M of 4 and 8 is 8. hope this helps!
Least Common Multiple (LCM) of 4 and 8 is 8.

What is the value of
CNIC
?
81
16
16
81
16
81
81
16
PLEASE HELP!!!!!!!!!

Answers

Answer:

10.5

Step-by-step explanation:

Find the slope. Simplify completely. ​

Answers

4/1 or 4. I hope this helps!

In what place is the digit 1 in the number 607.912
hundreds
tens
tenths
hundredths

Answers

Answer:

tenths.........

Step-by-step explanation:

.....is the answer

If somebody puts links report them

Find the value of x. Write your answer in simplest form.

Answers

By using Pythagoras Theorem:-

(Hypotenuse)² = (Base)²+ (Perpendicular)²

Taking, Hypotenuse As H

Base As B

Perpendicular As P

_________________________

Solving The Question

H²= B²+ P²

[tex](9 \sqrt{2} ) {}^{2} = x {}^{2} + {x}^{2} \\ \\ \implies \: 81 \times 2 = 2x {}^{2} \\ \\ \implies162 = 2x {}^{2} \\ \\ \implies \frac{162}{2} = x {}^{2} \\ \\ \implies \cancel\frac{162}{2} = x {}^{2} \\ \\ \implies81 = {x}^{2} \\ \\ \implies x = \sqrt{81} \\ \\ \implies \: x = 9[/tex]

Hope This Helps You ❤️

Graph the image of this triangle after a dilation with a scale factor 1/2 centered origin

Answers

i dont know this questions

Is it possible to find two data sets A and B such that A has a greater median and mode, while B has a greater average and range? If you think the answer is yes, provide an example. If you think the answer is no, explain why not.

Answers

Answer:

For a data set of N elements:

{x₁, x₂, ..., xₙ}

The median is the middle value (or the average of the two middle values)

The average or mean is:

[tex]m = \frac{x_1 + ... + x_n}{N}[/tex]

The mode is the value that is more repeated.

The range is the difference between the largest value and the smallest value.

Now, let's try to construct two sets A and B that meet the required conditions:

Let's suppose two sets of 5 values each:

A = {2, 2, 3, 4, 5}

The median of A is 3.

The range of A is = 5 - 2 = 3

The average of A is: (2 + 2 +3 +4 +5)/5 = 16/5

And the value "2" appears two times, so the mode is 2.

Now, let's try to find a data set B such that:

The mode is smaller than 2  (so for example, we can have a "1" that repeats two times)

The median is smaller than 3 (let's have a median equal to 2)

The average is larger than 16/5

The range is larger than 3

This is ratter simple:

B = {1, 1, 2, 6, 9}

The median of B is 2.

The mode of B is 1

The range of B is: 9 - 1 = 8

The average of B is: (1 + 1 + 2 + 6 + 9)/5 = 19/5

So, we just found an example for two data sets A and B such that A has a greater median and mode, while B has a greater average and range.

So the answer is yes, it is possible.

Find the perimeter of an
octagon with each side
measuring 9 cm.?

Answers


9(the measurement of each side)x8(the amount of sides)=72
Answer 72cm

Currently, there are 1,460 wolves in Scataway National Park. If the population of wolves is growing at a rate of 6% every year,
which function represents the number of wolves in Scataway National Park in tyears?
OA W0 = 1,460(1.06)
B. WO = 1,460(0.94)
OC M6 = 1,460(0.06)
OD. WO = (1,460)(1.06)

Answers

Answer:

[tex]P(t) = 1460(1.06)^t[/tex]

Step-by-step explanation:

Exponential equation for population growth:

The exponential equation for a population after t years is given by:

[tex]P(t) = P(0)(1+r)^t[/tex]

In which P(0) is the initial population and r is the growth rate, as a decimal.

Currently, there are 1,460 wolves in Scataway National Park.

This means that [tex]P(0) = 1460[/tex]

Growing at a rate of 6% every year:

This means that [tex]r = 0.06[/tex]. So

[tex]P(t) = P(0)(1+r)^t[/tex]

[tex]P(t) = 1460(1+0.06)^t[/tex]

[tex]P(t) = 1460(1.06)^t[/tex]

Answer:

Step-by-step explanation:

three hundred forty seven and three hundred ninety two thousandths in standard form​

Answers

Answer:

347,392

Step-by-step explanation:

yes

find the area of a rectangle with a length of (5x+2) and width of (2x-1)

Answers

Step-by-step explanation:

the rectangle area=L*W

(5x+2)(2x-1)

10x^2-5x+4x-2

10x^2-x-2

All sides of quadrilateral ABCD are tangent to circle P.
What is the perimeter of the quadrilateral below?

Answers

Answer:

44.4 units

Step-by-step explanation:

Recall: 2 tangents drawn from an external point from a circle are congruent

Perimeter of the quadrilateral = AB + BC + CD + AD

AB = 3.1 + 8 = 11.1

BC = 3.1 + 8 = 11.1

CD = 11.1 (given)

AD = 8 + 3.1 = 11.1

Perimeter = 11.1 + 11.1 + 11.1 + 11.1

= 44.4 units

FINDING PERIMETER need help right now

Answers

Answer:

if you want to find perimeter you must do addition for the corners. For example on long side in the regtangle the number is 4. And the short side is 6. The one thing we must do is addition. Than the answer will be 10. You're welcome.

please help me with 1 to 4!! <33

Answers

if you meant to put a link there is none

Andy cycles a distance of 30 km at an average speed of 24 km/h.
He then runs a distance of 12 km at an average speed of 8 km/h.
Work out the total time Andy takes.
Give your answer in hours and minutes.

Answers

Step-by-step explanation:

Total time taken=(30/24+12/8)

=(1.25+1.5)

=2.75 hrs

=165 minutes

=2 hrs and 45 minutes

formula used: v=d/t

or,d=v×t

or,t=d/v which is the master formula used in the solution of this problem.

If you are satisfied with my answer then please, give brainliest.

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