b) Incomes of a group of 2000 employees in a certain company were found to be normally distributed with mean Rs.5500 and standard deviation Rs 1000. Find the expected number of employees with income. i) below 5000 ii) above 8000 iii) the lowest income of high ranked 15% of employers.

Assume that the square footage of a residential house in the US is normally distributed with a mean=1000 and standard deviation=150 square feet. If we select a random house what is the probability that it will be at most 1050 square feet?

A construction zone on a highway has a posted speed limit of 40 miles per hours. The speeds of vehicles passing through this construction zone are normally distributed with a mean of 46 mph and a standard deviation of 4 mph.  a) what percentage of vehicles exceed the speed limit? (round to 4 decimals) b) If the police wish to ticket only those drivers whose speed falls in the upper 20th percentile, what is the minimum speed of a driver they will be ticketed? (round answer to 2 decimals)

Confidence intervals