10.3

1.

  1. Right-tailed test;15d.f.; t0.01 = 2.602

  2. Left-tailed test; 19 d.f.; -t0.05= -1.729

  3. two-tailed test;12 d.f.; -t0.025= -2.179 and t0.025 = 2.179

2.

  1. 22 d.f.; t0.1= 1.321

  2. 39 d.f.; -t0.01 = -2.426

  3. 32 d.f.; -t0.005= -2.733 and t0.005= 2.733

3.

  1. to= -1.379

  2. 23 d.f.; -t0.05= -1.714

  3. Skip this problem.

  4. there’s not enough evidence to reject the null hypothesis because to= -1.379 > -1.714 4.

  5. to= 2.67

(b)24d.f; t0.1= 1.318

  1. Skip this problem.

  2. there’s enough evidence to reject the null hypothesi; it’s right-tailes test and test statistic is > than critical value

5.**

  1. to= 2.502

  2. two-tailed test; 22 d.f.; -t0.005 = -2.819 and t0.005= 2.819

  3. Skip this problem.

  4. there’s not enough evidence to reject null hypothesis because the test statistics is between the critical values

  5. Lower bound: 99.36; Upper bound = 110.21

11.

Ho: mean = 67

Ha: mean > 67

  1. P-value = 0.02; We expect 2 out of 100 sample to have a mean of $73 or > from population whose mean = $67

  2. P-value = 0.02 < 0.05; there’s enough evidence to support that the mean $ amount withdrawn from a payease ATM is > than the mean from a standard ATM, that is >$67

13.

Ho: = 22

Ha: > 22

  1. the sample is obtained fro ma random sampling and n= 200 > 30; the sample size is less than 5% of P

  2. CLASSICAL APPROACH: to= 2.176 > t0.05= 1.660, reject null hypothesis

  3. there’s sufficient evidence to conclude that students who complete the core curriculum are scoring above 22 on the math portion of the ACT

15.

to = -4.553; to < t0.01 = 2.718, reject null hypothesis

Tthere’s enough evidence to conclude tha the mean hippocampal vlume in alcoholic adolescents is < 9.02

17.

right-tailed test to= 0.813 < 1.685 Do not reject null hypothesis

there’s not sufficient evidence to conclude that the mean Fico score of high income individuals is > 703.5

19.

Lower bound: 33.44; Upper vound: 42.36

The interval includes 40.7 years, there is not enough evidence to conclude tha tthe mean age of a death-row inmate has changed since 2002

10.4

1.

  1. Right-tailed ; Chi-Square = 28,869

  2. Left-tailed; Chi-Square = 14.041

  3. two-tailed test; Chi-Square = 16.047 and 45.722

3.

  1. Chi-Square= 20.496

  2. 13.091

  3. Skip this problem

(d)Do not reject null hypothesis because Chi-Square is > than critical value

13.

Note. The sample standard deviation of the data shown is.\(15.205043\). You will have to knit this to see the number though.

Chi-Square = 6.422; critical value = 3.325; Chi-Square is > than 3.325

Do not reject null hypothesis; there’s not enough evdience to conclude that the standard deviatiom is < tha 18 seconds

15.

Chi-Square = 15.639; crtal value = 15.659; reject null hypothesis

there’s enough evidence to conclude Rose is more consisten tthan the other players