Suppose a Population Was Normally Distributed With $\mu$ = 10 And $\sigma$

Essay

Suppose a population was normally distributed with $\mu$ = 10 and $\sigma$ = 2.
a. What proportion of the scores would lie between 7.5 and 12.5?
b. What proportion would lie between 7.5 and 10.5?
c. What proportion would lie between 10.5 and 12.5?
d. What score would separate the lower 40% of the population from the upper 60%?
e. If there were 250 members of the population, how many would be expected to score 11 or more?
f. What proportion would be expected to score 9 or more?g. Does this problem deal with a theoretical or an empirical distribution?