10.3

1.

  1. t0.01=2.602

  2. -t0.05=-1.73

  3. +/-t0.025=+/-2.18

2.

  1. t0.1=1.321

  2. -t0.01=-2.43

  3. +/-0.005=+/-2.74

3.

  1. t0=-1.38

  2. -t0.05=-1.714

  3. skip

  4. the test statistic is greater than the critical value, so there is not enough evidence for the researcher to reject the null hypothesis

4.

  1. t0=2.674

  2. t0.1=1.32

  3. skip

  4. reject the null hypothesis because it is a right tailed test with a test stastic greater than the critical value

5.

  1. t0=2.502

  2. -t0.005=-2.819; t0.005=2.819

  3. skip

  4. there is not enough evidence to reject

  5. lower:99.4 ;upper:110.2; do not reject the null hypothesis

11.

Ho: mu=$67

H1: mu>$67

  1. 0.02 probability of obtaining a sample mean greater than $73. if 100 random samples of 40 were taken from a population with a mean of 67 then only 2 samples would be above $73

  2. reject the null hypothesis because the p-value is low

13.

Ho: mu=22

H1: mu>22

  1. the scores are independent because the sample is random and the size is large

  2. classical, t0=2.18>t0.05=1.66;p-value, 0.01<p-value<0.02; both reject the null hypothesis

  3. there is enough evidence to claim that students who complete core curriculum score above a 22 on the ACT

15.

p-value<0.0005<alpha=.01; reject the null hypothesis

17.

0.25>p-value>0.20>alpha=.05; do not reject the null hypothesis

19.

(35.44, 42.36), not enough information to conclude that the mean age has changed

10.4

1.

  1. x^2 0.05=28.87

  2. x^2 0.9=14.04

  3. x^2 0.975=16.047; x^2 0.025=83.3

3.

  1. x^2 0=20.5

  2. x^2 0.95=13.1

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

  4. do not reject null hypothesis

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.

0.10<p-value<0.90; do not reject null hypothesis

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.

0.05<p-value<0.10; reject the null hypothesis