Site preparation for new housing developments for tracts of 40 houses is normally distributed with a mean of 250 workdays and a standard deviation of 25 workdays.
a.Find the probability that the site will not be completed within 280 days
b. The probability that the site is completed in less than 225 workdays or it takes more than 275 workdays
c. Find the number of workdays that represent the probability .99 that the site is completed.
d. Find the probability that the site is completed between 260 and 280 workdays.