1.A study is conducted to determine if a newly designed text book is more helpful to learning the material than the old edition. The mean score on the final exam for a course using the old edition is 75. Ten randomly selected people who used the new text take the final exam. Their scores are shown in the table below.

PersonABCDEFGHIJTest Score96836893798892708673

Use a0.05

0.05

significance level to test the claim that people do better with the new edition. Assume the standard deviation is 10.4. (Note: You may wish to use statistical software.)

(a) What kind of test should be used?

A.One-Tailed

B.Two-Tailed

C.It does not matter.

(b) The test statistic is

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(rounded to 2 decimals).(c) The P-value is

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(d) Is there sufficient evidence to support the claim that people do better than 75 on this exam?

A.No

B.Yes

(e) Construct a95

95

% confidence interval for the mean score for students using the new text.

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2.The Census Bureau reports that 82% of Americans over the age of 25 are high school graduates. A survey of randomly selected residents of certain county included 1130 who were over the age of 25, and 949 of them were high school graduates.

(a)

Find the mean and standard deviation for the number of high school graduates in groups of 1130 Americans over the age of 25.

Mean =

Standard deviation =

(b)

Is that county result of 949 unusually high, or low, or neither?

(Enter HIGH or LOW or NEITHER)

3.The rates of on-time flights for commercial jets are continuously tracked by the U.S. Department of Transportation. Recently, Southwest Air had the best rate with 80 % of its flights arriving on time. A test is conducted by randomly selecting18

Southwest flights and observing whether they arrive on time.

(a)Find the probability that at least17

flights arrive on time.

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(b)

Would it be unusual for Southwest to have3

flights arrive late?

(Enter YES or NO)

4.BlueSky Air has the best on-time arrival rate with 80% of its flights arriving on time. A test is conducted by randomly selecting 16 BlueSky Air flights and observing whether they arrive on time.

What is the probability that 2 flights of BlueSky Air arrive late? (Please carry answers to at least six decimal places in intermediate steps. Give your final answer to the nearest four decimal places).

Probability (as a proportion)