7) The average commute to work (one way) is 20 minutes according to the 2005 American Community Survey. If we assume that commuting times are normally distributed and that the standard deviation is 5 minutes, what is the probability that a randomly selected commuter spends between 20- and 30-minutes commuting one way? (5 points)

State the Z value (s)_____________________________(2 points)

Statement_______________________________________(3 points)

8) Suppose that you have a sample of 25 Female Marines from a population of female Marines with a mean weight of 200 pounds ( = 200 ) and with standard deviation = 10.

a. What is the probability that the sample mean weight will be greater than 196 pounds (6 points) State the standard error. Standard Error______________(5 points)

State the Z value (s)_________________________________(2 points)

Statement___________________________________________(3 points)

b. A Sargent takes weights of a sample of 25 female Marines. Find the sample mean cut off weights for the Middle 90% of all female Marines from the sample size 25 taken from the population. (Round to a whole number) (6 points)

State the Z value (s)_____________________________________________________(2 points)

Statement_________________________________________________________________________(3 points)