1: F T F T F F T T F F F T T F 
2-6: B; C; B; C; E

7: a) Two-sample t-test
b) Let mu_R and mu_N be the mean weight of mussel meet for raft and natural groups, respectively.
Ha: mu_R-mu_N > 0
c) d.f.=134+46-2=178

8: Tukey's method: multiplier=q_(5,20,0.10)/sqrt(2)=3.736/sqrt(2)=2.642
Bonferroni's method: t_(20,0.1/10)=2.528
Bonferroni's method is better, because it has smaller multiplier. 

9) 
Source		DF	SS	MS	F	P-value
Treatment   	6	120	20	4	P-value < 0.005
Error	       63	315	 5	
Total	       69

10) H0: p_M-p_F=0 vs. Ha: p_M-p_F>0. p.hat_M=242/366=0.661, p.hat_F=257/423=0.608
p.hat=(242+257)/(366+423)=0.632
z=(p.hat_M-p.hat_F)/sqrt(p.hat*(1-p.hat)*(1/423+1/366))=0.053/0.0344=1.54
p-value=P(Z>1.54)=0.0618 > 0.05=alpha
Fail to reject null hypothesis. 

11) a) H0: mu_d=0 vs. Ha: mu_d>0
t=8/(27.9/sqrt(7))=0.759
df=7-1=6 p-value is between 0.2 and 0.25
Fail to reject the null hypothesis
b) The differences d1~d7 are random samples from a normal distribution with mean mu_d and SD sigma. 

12) a) H0: mu1-mu2=0 vs. mu1-mu2<0
sp=sqrt((60^2*35+75^2*29)/(35+29))=67.2
t=(110-150)/(67.2*sqrt(1/36+1/30))=-2.41
d.f.=64
P-value is between 0.005 and 0.01. Reject the null hypothesis. 
b) (150-110) +/- 2.678*67.2*sqrt(1/36+1/30) = 40 +/- 44.5
[-4.5,84.5]