1. In N(100, 400), find:

a. The proportion of the values greater than 70

b. The values of y within the central 90% of the distribution

c. The smallest value of y that exceeds 85% of the distribution

d. The largest value of y that is below 60% of the distribution

2. Assume that Graduate Record Examination (GRE) scores follow a normal distribution with a mean of 1000 and a standard deviation of 200.

a. What percentage of graduates who take this exam have GRE scores greater than 750?

b. What GRE score separates the upper 30% of graduates from the other 70%?

c. Between what values are the scores of the central 90% of the graduates?

d. How likely is it that a randomly selected graduate will be one who has a GRE score greater than 1000? e. How likely is it that a random sample of 10 graduates will contain more than 7 who have GRE scores greater than 1000?

f. Suppose that a group of 10 graduates contains 8 who have GRE scores greater than 1000.

i. Does this appear to be a random sample?

ii. Why?