Answer:
B) μD = 0.60 ± 0.10(1.397)
Step-by-step explanation:
The confidence interval is given by:

Where
MD=60
n=9
df=n-1=8


Then the confidence interval is
μD=0.60±1.397*(0.3/√9)
μD=0.60±0.10*(1.397)
answer: it would be one solution, becasue the variables are different and the constants dont matter, since the variables are different
The anwser to your problem is 1,800
I would have to go with B as your answer
76%*97
=73.72
I hope this helps.
Comment if you need further explanation.