10.3

1.

  1. 2.602

  2. -1.729

  3. +/- 2.179

2.

  1. 1.321

  2. -2.426

  3. +/- 2.738

3.

  1. -1.38

  2. -1.714

  3. skip

  4. No, they will not reject the null hypothesis, bc it does not fall in the critical region.

4.

  1. 2.67

  2. 1.318

  3. skip

  4. The researcher should reject the null hypothesis bc the test statistic falls in the critical region.

5.

  1. 2.5

  2. 2.819

  3. skip

  4. The researcher should not reject the null hypothesis, bc the test statistic does not fall in either of the critical regions.

  5. 99% CI–> 99.39, 110.21 This interval captures the null hypothesis.

11.

Ho: pop. mean = $67

H1: pop. mean > $67

  1. It represents a kind of proportion- if the null hypothesis is true (which is what we’re testing for), then the result the null hypothesis suggests should be expected in about 2 out of every 100 samples.

  2. We reject the null hypothesis as 0.02 is less than the level of significance, which is alpha= 0.05.

13.

Ho: pop. mean= 22

H1: pop. mean > 22

  1. Sample is random, n>/= 30; The values being sampled are independent of each other. All conditions satisfied.

  2. test statistic = a/b 2.176 CV= 1.653, and bc 2.176 is larger than the critical value, we reject the null hypothesis.

  3. It’s reasonable to believe that these students who are receiving higher mean scores on the math ACT than the null hypothesis pop. mean are ready for college-level math.

15.

Test statistic = a/b -4.553, with a CV of -2.718. Since the test statistic falls within the critical region, we reject the null hypothesis, suggesting that the volumes of adolescent’s hippocampuses with alcoholic problems are smaller than the normal volume.

17.

Test statistic= 0.813 CV= 1.685 We do not reject the null hypothesis, as the test statistic does not fall within the critical region. So, there is not enough evidence to suggest that high income individuals have higher credit scores.

19.

(35.432, 42.368) The interval does capture the null hypothesis age, so we do not reject it.

10.4

1.

  1. 28.869

  2. 14.041

  3. 16.047, 45.722

3.

  1. Test statistic= a/b 20.496

  2. CV= a/b 13.091

  3. Skip but feel free to sketch on a piece of paper for your benefit.

  4. Null hypothesis will not be rejected as the test statistic does not fall within the critical region.

13. Feel free to use any method you want. If you use the classical method please report the value of your test statistic and your decision. Likewise if you use the pvalue method please state your pvalue and your decision. Hint: The sample standard deviation (s) is 15.20.

Classical Method: Test Statistic: a/b 6.418 CV= a/b 3.33 We do not reject the null hypothesis, as the test statistic does not fall within the critical region. So, there isn’t enough evidence to say that the st. dev. of the wait time is less than 18 sec.

15. Feel free to use any method you want. If you use the classical method please report the value of the test statistic and your decision. Likewise if you use the pvalue method please state your pvalue and your decision.

Classical Method: Test Statistic= a/b 15.639 CV= a/b 15.658 We reject the null hypothesis as the test statistic falls within the critical region.
So, there is enough evidence to suggest that Derrick Rose is more consistent than other shooting guards.