Answer:
Step-by-step explanation:
Given that a part of a study of the treatment of anemia in cattle, researchers measured the concentration of selenium in the blood of 36 cows who had been given a dietary supplement of selenium (2 mg/day) for one year.
If x is the selenium concentration then
X has mean= 6.21 mg/dl
and std dev = 1.84
Sample size n = 36
std error of sample = 
Margin of error for 95%

Confidence interval = 
85/100=34/?
85÷2.5=34
100÷2.5=40
34/40=34/? ?=40
there were 40 questions
Answer: 5/3 = 1 10/6
Step-by-step explanation: This is the right answer.