The average number of drop-outs for a school district has been 305 per year with a standard deviation of 50. What is the probability that next year the number of drop-outs will be

a. less than 250? ___________

b. less than 300? ___________

c. more than 350? ___________

d. more than 400? ___________

e. between 250 and 350? ___________

f. between 300 and 350? ___________ g. between 350 and 375? __________