Stat lab help??????

Question

suppose the length of the pregnancies of a certain animal are approximately normally distributed with mean u=250 days and standard deviation o= 12 days.

If 100 pregnant individuals were selected independently from this population, we would expect_______ pregnancies to last exactly 246 days

if 100 pregnant individuals were selected independently from this population, we would expect______ pregnancies to last more than 246 days.

Answer 1

1) first we want to find out what the probability that the average pregnancies day is 246 days, which is P(X_bar = 246) = 0, so we would expect pregnancies to last exactly 246 days is ZERO

2) very similar to the previous question but now we want to find P(X_bar > 246) then use 100*P(X_bar > 246)

The most difficult thing here is to find P(X_bar > 246) but we know the pregnancy days are approximately normally distributed, so finding P(X_bar > 246) is relatively easy.