Automobiles Purchased An automobile owner found that 20years ago, 72% of Americans said that they would prefer to purchase an American automobile. He believes that the number differs from72% today. He selected a random sample of 43 Americans and found that 38 said that they would prefer an American automobile. Can it be concluded that the percentage today differs from 72% ? At a-0.10 is he correct? Use the critical value method with tables.

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Automobiles Purchased An automobile owner found that 20years ago, 72% of Americans said that they would prefer to purchase an American automobile. He believes that the number differs from72% today. He selected a random sample of 43 Americans and found that 38 said that they would prefer an American automobile. Can it be concluded that the percentage today differs from 72% ? At a-0.10 is he correct? Use the critical value method with tables.

 

Use u1 for the mean out-of-state tuition of private colleges.

The 95confidence interval for the  difference of the means is <u1-u2<

 

 

 

 

 

 

 

 

 

Bartelby

Ages of Homes Whiting, Indiana leads thee "Top 100  Cities with the Oldest Houses" list with the average age of houses being 

66.4 years. Farther down the list resides Franklin, Pennsylvania, with an average house age of 59.4  years. Researchers selected a random sample of 22  houses from Whiting and 

19  houses from Franklin and obtained the following statistics. At 

α=0.05, can it be concluded that the houses in Whiting are older? Use the P-value method. Assume the variables are normally distributed and the variances are unequal.

 

 

Whiting

Franklin

Mean age (in years)

61.6

59.7

Standard deviation (in years)

5.4

3.9

Use μ1 for the average age of houses in Whiting.

 (a) State the hypotheses and identify the claim.

H0: claim/not claim 

H1: claim/not claim

This hypothesis test is a one-tailed/two-tailed test.

 (b) Compute the test value. Round the answer to at least three decimal places.

t=

(c) Find the interval for the P-value.

The correct interval is

 (d) Make the decision.

Reject/do not reject the null hypothesis.

(e) Summarize the results.

There is/is not enough evidence to support the claim that the houses in Whiting are older.

Age of Senators The average age of senators in the108th Congress was 59  years. If the standard deviation was 12.5 years, find the z -scores corresponding to the oldest and youngest senators of age 88  and 46 . Round z  scores to two decimal places.

The z-score corresponding to the oldest senator of age 

  is? 

 

.

 

The z-score corresponding to the youngest senator of age is?

 

 

PGA Golf Scores At a recent PGA tournament (the Honda Classic at Palm Beach Gardens, Florida) the following scores were posted for eleven randomly selected golfers for two consecutive days. At 

α=0.20, is there evidence of a difference in mean scores for the two days? Assume the variables are normally or approximately normally distributed and use μD for the mean on Thursday minus the mean on Friday.

Golfer 1 2 3 4 5 6 7 8 9 10 11

Thursday 69 70 68 70 68 68 65 67 65 64 66

Friday 75 67 74 70 67 68 70 69 71 72 69

(a) State the hypotheses.

H0: claim/do not claim?

H1: claim/do not claim?

This hypothesis test is one tailed/two tailed?

(b) Find the critical value. Enter the answers in ascending order and rounded to at least three decimal places.

Critical value=

Compute the test value.  Round score values to at least  three decimals places.

t=

Make the decision.

Reject/Do not reject the null hypothesis

(e) Summarize the results.

There is/is not (Choose one) sufficient evidence to support the claim

 

 

 

 

   

 

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