1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
scZoUnD [109]
3 years ago
9

An article in the National Geographic News ("U.S. Racking Up Huge Sleep Debt," February 24, 2005) argues that Americans are incr

easingly skimping on their sleep. A researcher in a small Midwestern town wants to estimate the mean weekday sleep time of its adult residents. He takes a random sample of 80 adult residents and records their weekday mean sleep time as 6.4 hours. Assume that the population standard deviation is fairly stable at 1.8 hours. Use Table 1.
a.
Calculate a 95% confidence interval for the population mean weekday sleep time of all adult residents of this Midwestern town. (Round intermediate calculations to 4 decimal places, "z" value and final answers to 2 decimal places.)



Confidence interval to


b.
Can we conclude with 95% confidence that the mean sleep time of all adult residents in this Midwestern town is not 7 hours?

Yes, since the confidence interval contains the value 7.
Yes, since the confidence interval does not contain the value 7.
No, since the confidence interval contains the value 7.
No, since the confidence interval does not contain the value 7.
Mathematics
2 answers:
Katyanochek1 [597]3 years ago
5 0

Answer:

a)6 hours is the time  to achieve 95% confidence level for the population.

b)Yes, because the confidence interval does not have the value 7

erastovalidia [21]3 years ago
3 0

Answer:

a) The 95% confidence interval for the population mean weekday sleep time of all adult residents of this Midwestern town is (6.01 hours, 6.74 hours).

b) Yes, since the confidence interval does not contain the value 7.

Step-by-step explanation:

In the question a, we calculate the 95% confidence interval.

a)

We have that to find our \alpha level, that is the subtraction of 1 by the confidence interval divided by 2. So:

\alpha = \frac{1-0.95}{2} = 0.025

Now, we have to find z in the Ztable as such z has a pvalue of 1-\alpha.

So it is z with a pvalue of 1-0.025 = 0.975, so z = 1.96

Now, find M as such

M = z*\frac{\sigma}{\sqrt{n}}  = 1.96*\frac{1.8}{\sqrt{80}} = 0.3944

The lower end of the interval is the mean subtracted by M. So it is 6.4 - 0.3944 = 6.01 hours.

The upper end of the interval is the mean added to M. So it is 6.4 + 0.3944 = 6.74 hours.

The 95% confidence interval for the population mean weekday sleep time of all adult residents of this Midwestern town is (6.01 hours, 6.74 hours).

b.

Can we conclude with 95% confidence that the mean sleep time of all adult residents in this Midwestern town is not 7 hours?

The 95% confidence interval does not contain 7 hours, so the correct answer is

Yes, since the confidence interval does not contain the value 7.

You might be interested in
Match the Mixed Number to the Improper Fraction
Liono4ka [1.6K]

Answer:

15/4=3 3/4

21/4= 5 1/4

5/4= 1 1/4

28/4=7

Step-by-step explanation:

Divide the numerator by denominator: 15/4=3 r3

After that, use 3 as the whole number part. The remainder goes the the mixed number's numerator. The Divisor is now the denominator.

Use this method for others

7 0
2 years ago
Read 2 more answers
Evaluate the function f(x) = 2x3 - 6x + 1 for f(-2).
erma4kov [3.2K]

Answer:

- 3

Step-by-step explanation:

f(x) = 2 {x}^{3}  - 6x + 1 \\ plugging \: x =  - 2 \\ f( - 2) = 2( { - 2})^{3}  - 6( - 2)+ 1  \\  = 2 \times ( - 8) + 12 + 1 \\  =  - 16 + 13 \\  =  - 3 \\ f( - 2) =  - 3

7 0
3 years ago
X 11 -5 2 16 Y 6 -13 10 13 Is this relation a function? YES OR NO​
Tasya [4]

Answer:

this is a function I beleive

hope this helps

5 0
3 years ago
Read 2 more answers
68 increased by 75%
mash [69]

Let's see -

Follow the directions below to get your answer -

0.75 × 68 = 51

51 + 68 = 119

So, 119 is your answer

68 increased by 75% is 119.

↑   ↑   ↑  Hope this helps! :D


3 0
2 years ago
Read 2 more answers
<img src="https://tex.z-dn.net/?f=%20-%20%20%5Cfrac%7B9%7D%7B5%7D%20%20%5Cdiv%204" id="TexFormula1" title=" - \frac{9}{5} \div
raketka [301]

Your answer would be negative 9/20

3 0
3 years ago
Other questions:
  • Rectangle ABCD with sides of 7 and 5 and rectangle mono with sides of 21 and 15
    6·1 answer
  • Principal = $450<br> rate = 5%<br> time = 4 years<br> simple interest =<br> compound interest =
    13·2 answers
  • Simultaneous equations:
    6·1 answer
  • What is the length of leg s of the triangle below?
    7·1 answer
  • -9 &lt; x &lt;-2. <br> I need help
    12·1 answer
  • Find the positive square root of 7+4sq.rt3
    10·1 answer
  • A mouse is moving through a maze and must make four turns where it can go either left or
    14·1 answer
  • Which expression is equivalent to 2(y + 11)<br><br> 2y + 22<br> 2y + 11<br> y + 22
    10·2 answers
  • Will give 30 points and Brainliest!!!!
    6·1 answer
  • Suppose that f'(4) = 3 , g'(4) = 7 , g(4) = 4 and g(x) not= to 4 for xnot= to 4 . then cmpute lim xgose to 4 f(g(x))/x-4-f(4)/x-
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!