Sleep habits of New Yorkers. New York is known as the city that never sleeps". A random sample of 25 New Yorkers were asked how much sleep they get per night. Statistical summaries of these data are shown below. The point estimate suggests New Yorkers sleep less than 8 hours a night on average. Is the result statistically signicant? n x s min max25 7.73 0.77 6.17 9.78(a) Write the hypotheses in symbols and in words.(b) Check conditions, then calculate the test statistic, T, and the associated degrees of freedom.(c) Find and interpret the p-value in this context. Drawing a picture may be helpful.(d) What is the conclusion of the hypothesis test?(e) If you were to construct a 90% condence interval that corresponded to this hypothesis test, would you expect 8 hours to be in the interval?

Step-by-step explanation:

1.

the null hypothesis:

H0: u = 8 hours ( new Yorkers sleep for 8 hours)

The alternate hypothesis;

H1: u ≠ 8 hours ( new Yorkers sleep less than 8 hours)

b.

test statistic

t = (barX - u)/s/√n

= 7.73-8/0.77/√25

= -1.7532

degree of freedom = n-1

= 25-1 = 24

c.

p(value)

= p(t < -1.7532)

= 0.046

obviously we can see that the p value is less than 0.05 alpha level so we reject the null hypothesis.

d

The data gives strong evidence that new Yorkers sleep less than 8 hours on average every night.

e.

at 90% level of confidence

we have

7.73-0.26334, 7.73+0.26334

= 7.466, 7.993

please check attachment

thank you!

15%

step-by-step explanation:

use the table and count the number of guesses that has two correct answers.

the following are two correct answers

10010, 01100, 11000

a total of 3 numbers having 2 correct guesses out of 20 questions.

probability of getting 2 correct guesses = the number of questions getting 2 correct answers / total number of questions.

= 3/20

to convert it into percent multiply by 100, we get

= 3/20 * 100

= 15%

the answer is 15%

you.