To estimate likely expenditure by customers at a new supermarket, a sample of till slips from a similar supermarket describing the weekly amounts spent by 600 randomly selected customers was analyzed. These data were found to be approximately normally distributed with a mean of 60 and a standard deviation of 20. Using this knowledge find the following information for shoppers at the new supermarket: (12 Marks)

1. The value below which:

a. 60% of the customers are expected to spend,

b. 55% of the customers are expected to spend.

2. The value expected to be exceeded by:

a. 15% of the customers,

b. 75% of the customers

3. The value below which:

a. 450 of the shoppers are expected to spend.

b. 150 of the shoppers are expected to spend.