The amount of time a bank teller spend,. ;:' "'~ with each customer has a population mean, J.L, 01 3.10 minutes and standard deviation, if, of 0040 minute. If you select a random sample of 16 customers, a. what is the probability that the mean time spent

 The amount of time a bank teller spend,.
;:' "'~ with each customer has a population mean, J.L, 01
3.10 minutes and standard deviation, if, of 0040 minute. If
you select a random sample of 16 customers,
a. what is the probability that the mean time spent per customer
is at least 3 minutes?
b. there is an 85% chance that the sample mean is less than
how many minutes?
c. What assumption must you make in order to soh.:
(a) and (b)?
d. If you select a random sample of 64 customers, there is
an 85% chance that the sample mean is less than ho\\
many minutes'.