I know that a lifetime of flowers in a bouquet 1 buy my wife

I know that a lifetime of flowers in a bouquet 1 buy my wife is normally distributed with a mean of 6 days and a standard deviation of 1.4 days.
a. what is the probability that one randomly selected such bouquet will last more than 7 days?
b. what is the probability that the mean lifetime of 5 bouquets will be less than 5.5 days?
c. as the sample size of bouquets increases will the standard error of the mean go up or down?

Solution