Homework #11

11.38

(a) H₀ : mu_D = 0, H₁: mu_D > 0

(b) first use calculator to find D-bar = 1.89, S_D = 4.37
then use formula on page 629 to find the observed test statistic t = 1.30
use the table to find 0.10 < P-value < 0.20

(c) will not reject H₀ , there is not enough evidence to show that the drug is effective

11.42
This is an independent sample study

(a) H₀ : mu₁ = mu₂, H₁: mu₁  > mu₂

(b) Use the formula on page 646

S_P =  27.6

the observed test statistic =  4.00

the degrees of freedom = 16+16-2=30

Use the table, P-value is less than 0.005

reject the null hypothesis, data show evidence that new method is better than the old one.

Chapter 12 Exercises:

12.30

(a)  H₀ : mu₁ = mu₂= mu₃
        H₁: not all the same

(b) yes, because P-value is close to 0.
 

12.34
(a)  H₀ : mu₁ = mu₂= mu₃
        H₁: not all the same
(b) This part is a little beyond what is required.

Source         SS            DF                    MS                                F
Between   0.27664      3-1=2           0.27664/2=0.13832      0.13832/0.00815= 16.97
Within      0.0978       15-3=12       0.0978/12=0.00815
Total         0.37444

Note that: SS(within) = SST-SSB = 0.37444-0.27664=0.0978

For the exam: should know that F = MSB/MSW, DF₁=I-1, DF₂=n-I