A professor at a university wants to estimate the average number of hours of sleep the students get during exam week. The professor wants to find a sample mean that is within 4.266 hours of the true average for all college students at the university with 99% conconfidence. If the professor knows the standard deviation of the sleep times for all college students is 2.539, what sample size will need to be taken

Answers

Answer 1

Answer:

The sample size is [tex]n = 2[/tex]

Step-by-step explanation:

From the question we are told that

   The margin of error is  E =4.266

    The standard deviation is  [tex]\sigma = 2.539[/tex]

From the question we are told the confidence level is  99% , hence the level of significance is    

      [tex]\alpha = (100 - 99 ) \%[/tex]

=>   [tex]\alpha = 0.01[/tex]

Generally from the normal distribution table the critical value  of  [tex]\frac{\alpha }{2}[/tex] is  

   [tex]Z_{\frac{\alpha }{2} } =  2.58[/tex]

Generally the sample size is mathematically represented as  

   [tex]n = [\frac{Z_{\frac{\alpha }{2} } *  \sigma }{E} ] ^2[/tex]

=>  [tex]n = [\frac{2.58  *  2.539  }{4.266} ] ^2[/tex]

=>  [tex]n = 2[/tex]


Related Questions



Please help! I need help on this ! I will give brainliest!


Find the equation of a line that is parallel to the line x = 12 and contains the point (-6,4).
The equation of the parallel line is . (Type an equation.)

Answers

Answer:

x = -6 and x = 12 are parallel

Step-by-step explanation:

they are both vertical lines, one crosses the x-axis at -6, the other at 12

An arrangement for one container needs to have at least 4 flowers in it and the total wholesale cost must be less than $12. At wholesale, lilies cost $2 per flower and roses cost $3 per flower. If x is the number of lilies and y is the number of roses, which graph represents the system of inequalities for this scenario?

Answers

Answer:

the answer is A on edge 2020

Step-by-step explanation:

hope this helped:)

Answer:

Your answer is A.

Step-by-step explanation:

which number completes the inequality?​

Answers

Answer:

1.08

Step-by-step explanation:

Answer:

B

Step-by-step explanation:

1.01<1.08<1.17<1.20

Which One Does Not Belong? Use a complete sentence to explain your choice.
5 + 5
2 + 8
9 + 1
3 +9

Answers

Answer:

3 +9 does not belong because it doesn't equal 10 like the rest of them do.

What is the value of 13.23 X0.19? a0.1047 c2.5137 d 251.37 b10.47​

Answers

Answer:

c

Step-by-step explanation:

Find the measure of angle "T"​

Answers

Answer:

T=71 degrees

Step-by-step explanation:

180- 82º-27º=71º

you got this! lmk if you need any more help! <33

answer:
t= 71 degrees

does anyone know the answer ?

Answers

Answer:

i think its inches per foot b/c it says what where the final units for this conversion i hope this is helpful.

Step-by-step explanation:

What is 0.031+10+2.2

Answers

Answer:

12.231

Step-by-step explanation:

you add them with the zeros

Answer:

12.231

Step-by-step explanation:

0.031+10+2.2

10.031+2.2

12.231

Christina has 50 coins consisting of quarters and dimes. The coins combined value is $9.50. Write a system of equation to determine how many quarters and dimes Christina has.

Answers

Answer:

Christina has 30 quarters and 20 dimes.

Step-by-step explanation:

Given that a quarter is worth 0.25 dollars and a dime is worth 0.10 dollars, if Christina has 50 coins and these add up to a total of $ 9.50, to determine the number of quarters and dimes that she has in her possession, the following calculation must be carried out, taking into account that the difference between a quarter and a dime is 0.15 dollars:

50 x 0.25 = 12.5

12.5 - 9.5 = 3

Thus, the difference between the value that Christina has and the value that she would have if all of her coins were quarters is 3 dollars. Thus, since 0.15 x 20 equals 3, of the 50 coins Christina has, 30 are quarters and 20 are dimes.

This is confirmed through the following equation:

30 x 0.25 + 20 x 0.1 = X

7.5 + 2 = X

9.5 = X

3. What is the slope of the line through the points (2, 5) and (6, 13)?

Answers

Answer:

m = 2

Step-by-step explanation:

[tex]m=\frac{rise}{run}=\frac{13-5}{6-2}=\frac{8}{4}=\boxed{2}[/tex]

Hope this helps.

In kite ABCD, BE = –x + 6 and ED = 0.5x. Determine the value of x in the kite shown. Question 2 options: A) x = –12 B) x = –3 C) x = 4 D) x = 9

Answers

Answer:

4

Step-by-step explanation:

–x + 6 = 0.5x

–(4) + 6 =.5(4)=2

-x-.5x=-6

-1.5x=-6

X=4

Answer:

x=4

Step-by-step explanation:I took the test

what is the range of f (x)=3 ^ x?

Answers

Answer:

it is 0 so that is x

Step-by-step explanation:

A student is training for the track team during the first three months of the year by
running for 30 minutes every day, while averaging 5 miles each day. Select the graph
that correctly shows the total miles the student ran during the time of his training
program.
1)
Hous
500
2)
200
Hours
10
23
8
50
3)

Answers

Answer:

uhhh

Step-by-step explanation:

Answer:

This question is to perfect to answer.

Please circle the zeros that do affect the value of the number and underline the
zeros that do not affect the value of the number.
Number: 600,345.0100

Answers

the zeros after 1 in the decimal dont affect the value, so from .0100, the last two zeros are unnecessary

of the following pair of variables indicate whether you would expect a positive, negative, or no correlation to exist.
Maximum daily temperature and cost to coolant house​

Answers

Answer:

B

Step-by-step explanation:

Bbbbb bbbbbbbbbbb

need answer thanks! only answer if you know please​!

Answers

Answer:

a) [tex]k \approx 0.0602\,\frac{1}{min}[/tex] ([tex]k\approx 6.02\,\frac{\%}{min}[/tex]), b) [tex]k \approx 0.0648\,\frac{1}{min}[/tex] ([tex]k \approx 6.48\,\frac{\%}{min}[/tex]), c) [tex]t_{1/2} \approx 60.274\,days[/tex], d) [tex]t_{1/2}\approx 4.305\,min[/tex], e) [tex]k \approx 0.3\,\frac{1}{min}[/tex] ([tex]k\approx 30\,\frac{\%}{min}[/tex]), f) [tex]k \approx 0.0120\,\frac{1}{min}[/tex] ([tex]k \approx 1.20\,\frac{\%}{min}[/tex]), g) [tex]k \approx 2.876\times 10^{-5}\,\frac{1}{yr}[/tex] ([tex]k \approx 2.876\times 10^{-3}\,\frac{\%}{yr}[/tex])

Step-by-step explanation:

All radioactive isotopes decay exponentially, the mass of the isotope as a function of time ([tex]m(t)[/tex]), measured in grams, is defined by:

[tex]m(t) = m_{o}\cdot e^{-k\cdot t}[/tex] (1)

Where:

[tex]m_{o}[/tex] - Initial mass of the isotope, measured in grams.

[tex]k[/tex] - Decay rate, measured in [tex]\frac{1}{min}[/tex] or [tex]\frac{1}{day}[/tex] or [tex]\frac{1}{yr}[/tex].

[tex]t[/tex] - Time, measured in minutes, days or years.

We define the decay rate in terms of half-life by using the following expression:

[tex]k = \frac{\ln 2}{t_{1/2}}[/tex] (2)

Where [tex]t_{1/2}[/tex] is the half-life of the isotope, measured in minutes or years.

Now we proceed to determine the missing values:

a) Polonium-200 ([tex]t_{1/2} = 11.5\,min[/tex])

[tex]k = \frac{\ln 2}{11.5\,min}[/tex]

[tex]k \approx 0.0602\,\frac{1}{min}[/tex]

b) Lead-194 ([tex]t_{1/2} = 10.7\,min[/tex])

[tex]k = \frac{\ln 2}{10.7\,min}[/tex]

[tex]k \approx 0.0648\,\frac{1}{min}[/tex]

c) Iodine-125 ([tex]k = 0.0115\,\frac{1}{day}[/tex])

[tex]t_{1/2} = \frac{\ln 2}{k}[/tex]

[tex]t_{1/2} = \frac{\ln 2}{0.0115\,\frac{1}{day} }[/tex]

[tex]t_{1/2} \approx 60.274\,days[/tex]

d) Kryption-75 ([tex]k = 0.161\,\frac{1}{min}[/tex])

[tex]t_{1/2} = \frac{\ln 2}{k}[/tex]

[tex]t_{1/2} = \frac{\ln 2}{0.161\,\frac{1}{min} }[/tex]

[tex]t_{1/2}\approx 4.305\,min[/tex]

e) Strontium-79 ([tex]t_{1/2} = 2.3\,min[/tex])

[tex]k = \frac{\ln 2}{2.3\,min}[/tex]

[tex]k \approx 0.3\,\frac{1}{min}[/tex]

f) Uranium-229 ([tex]t_{1/2} = 58\,min[/tex])

[tex]k = \frac{\ln 2}{58\,min}[/tex]

[tex]k \approx 0.0120\,\frac{1}{min}[/tex]

g) Plutonium-239 ([tex]t_{1/2} = 24100\,yr[/tex])

[tex]k = \frac{\ln 2}{24100\,yr}[/tex]

[tex]k \approx 2.876\times 10^{-5}\,\frac{1}{yr}[/tex]

The equation y - 3x - 5 = 0 when written in slope-intercept form is:
y = 3x - 5.
y=-3x + 5.
O y = 3x + 5.

Answers

Answer:

y = 3x + 5

Step-by-step explanation:

The zero seems to be a place holder to mess you up. Just ignore that it doesn't do anything. Add -3x and -5 to the both sides to create y = 3x + 5

I need help for this question.​

Answers

Answer:

the water rises 50ft  per minute so for 60min you have to multiply 60 x 50 which will be 3000ft in 60mins

Step-by-step explanation:

Monthly income of A and B are in the ratio 5:6. If A earns $3,300 less than B, then what is their total income?​

Answers

Answer:

a+3300=b

5a+3300=6a

minus 5a both sides

a=3300

3300*5=16500

3300*6=19800

16500+19800=36300

$36,300

Which graph is the most appropriate to describe the height of a candle burning at a constant rate? ​

Answers

Answer:

A

explanation:

When something has a constant rate of change, one quantity changes in relation to the other by a constant factor. One concrete example of this is the relation of distance rate and time

Answer:

c is the correct answer i think not sure

can you help me with this question please

Answers

Answer:

correct answer it's A

give me a like at least please

A local hamburger shop sold combined total 500 hamburgers and cheeseburgers the number of cheeseburgers old was three times the number of hamburger sold how many hamburgers were sold?

Answers

Answer:

125 hamburgers

Step-by-step explanation:

Let x be the number of hamburgers sold and 3x the number of cheeseburgers sold.

So:

x+3x=500

4x=500

x=125

So there are 125 hamburgers sold.

Which of the following best defines the sequence shown?
8, 24, 72, 216, ...

Answers

Answer:

Option (2)

Step-by-step explanation:

Given sequence is,

8, 24, 72, 216........

1st term of the sequence 'a' = 8

Ratio of 2nd and 1st term = [tex]\frac{24}{8}=3[/tex]

Ratio of 3rd and 2nd term = [tex]\frac{72}{24}=3[/tex]

There is a common ratio of 'r' = 3 in each successive and previous term.

Therefore, it's a geometric sequence.

Since, nth term of a geometric sequence is given by,

[tex]T_n=a(r)^{n-1}[/tex]

Therefore, function representing the geometric sequence is,

f(n) = [tex]f(n)=8(3)^{n-1}[/tex]

Option (2) is the answer.

Given the third term is 12 and the rate of change is 3. What is the first 5 terms ?

Answers

Answer:

6, 9, 12, 15, 18

Step-by-step explanation:

If the third term is 12, then to find the first term subtract 3 twice (or just subtract 6) to get 6. To find the rest of the terms add 3 accordingly. The equation to find this would be:

a_n = 6 + (n-1)3

The slope of the line y - 4x = -2 is 4.
False
O True

Answers

Answer:

True

Step-by-step explanation:

Set up the problem in slope intercept i.e y = mx + b. Add 4x to both sides to create y = 4x -2.  Any number or fraction in the m part is the slope. So the slope is 4.

True, the slope of the line y - 4x = -2 is 4.

The equation of a line in slope-intercept form with slope m is,

y = mx + c

Where 'c' is the y-intercept of the line.

Given that,

The equation of a line is,

y - 4x = - 2

Now it can be written in a slope-intercept form as,

y - 4x = - 2

Add 4x on both sides,

y - 4x + 4x = - 2 + 4x

y = 4x - 2

By comparing with slope - intercept of the equation,

Slope (m) = 4

Therefore, the statement is true.

To learn more about the equation of line visit:

https://brainly.com/question/18831322

#SPJ6

What do you divide by 90 to get 30?

Answers

Answer:

3

Step-by-step explanation:

3 times 30 = 90 then divide 90 and 30 you get 3

The answer is 2700 you reverse it. 90x30 which will get you 2700 and to double check you can then divide 2700 by 90

After soccer practice, 6 kids share 2 candy bars. Draw a model to show how much of the candy bar each kid gets (SHOW WORK)

Answers

Answer:

I don't know how to draw it out but...

Step-by-step explanation:

For every 3 kids there is 1 candy bar. For every 2 candy bars there are 6 kids. 2 candy bars divided by 6 kids equals, a third of a candy bar per kid.

ok so um yea plz help....and if you find them i will do 2 thingss............face reveil anddddddddd BRAINLEIST for you

Answers

Answer:

4

Step-by-step explanation:

all you have to do is divide 12 by 3

Answer:

4 if ur doing division or 3 over 12

                                       

Step-by-step explanation:

GIVING BRAINLIEST PLEASE HELPPPPPPPPPPPPP

Answers

Answer:

C

Step-by-step explanation:

The number of tips that the server gets is dependent on how many customers she serves.

Hope this helps!

Answer:

i dont understand

Step-by-step explanation:

but probably c

which triangle could be drawn as is it described

Answers

Answer:

you didnt add the attachment

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