HW11_skeleton

10.2

• 1. Statistically significant.
• 2. True.
• 3. False.
• 4. 2.33.
• 5. -1.28.
• 6. 1.645.

7.)

a) z0= 2.31 > z0.05 = 1.645; reject null hypothesis.
  
b) P-value = 0.0104 < alpha =0.05; reject null hypothesis.

11.)

a) z0= -1.49 is between -z0.025 = -1.96 and z0.025= 1.96;do not reject null hypothesis.
  
b) P-value = 0.1362 > a=0.05; do not reject null hypothesis.

 

17. z0=0.65 < z0.01=2.33; do not reject the null hypothesis.

18. z0=0.693 > z0.01=2.33; do not reject the null hypothesis.

 

10.3

1.)

a) t0.01 = 2.602.
  
b) -t0.05=-1.729.
  
c) +/-t0.025 = +/-2.179.

12.)

a) Ho: mean=63.7
   
   H1: mean > 63.7
  
b) Proportion of women higher than the critical value.
  
c) P-value=0.35 > alpha=0.1; reject null hypothesis.

13.)

a) Ho: mean = 22

   H1: mean > 22
  
b) the sample size is >  or = 30 and is random (200), sothe difference is large enough that the scores are independent.
  
c) t0= 2.176 > t0.05 = 1.660; reject null hypothesis.

d) students who complete the core curriculum are scoring above 22 on the ACT math section.

14.)

a) Ho: mean = 501

   H1: mean < 501

b) The sample size is > or = 30 and is a random sample of 100, so the difference is large enough that the scores are independent.
  
c) z0=1.379 < alpha 0.1; reject null hypothesis.

d) the mean score of the  random sample reading section scores is less than the normal mean score of 501.

15. t0= -4.553 < -t0.01 = -2.718cm^2; reject null hypothesis. The mean hippocampal volume in alcoholic adolescents is < the normal mean volume of 9.02cm^3.