1. A sample from 16 different farms across Quebec shows that the hay production in bales per acre is normally distributed N(100,50).
a. (2p )What is the probability that a random farm from this sample produces less than 80 bales/acre?
b. (2p) What is the probability that another random sample of nine farms has an average of less than 80 bales/acre?
c. (1p) Is the population mean known?
d. (2p) What can we learn from the central limit theorem in this case?
e. (3p) Calculate a 90 % confidence interval around the population mean.
f. (2p) Interpret: what does your answer in e) mean?
g. (2p) These nine farms were actually a pilot study. What is the minimal sample size needed to compute a 95 % confidence interval around the population mean?