An economist conducted a study to identify the

percentage of family income

allocated to the purchase of groceries. She surveyed a random sample of 50

families

and compiled the following numeric frequency distribution:

(a) Compute and interpret the (approximate) mean percentage of family income

allocated to grocery purchase. (Hint: Use the weighted average formula with

the midpoint of each interval as xi.)

(b) What is the maximum percentage of income that is allocated to grocery

purchase by:

(i) the lower 50% of families?

(ii) the lower 25% of families?

(c) 25% of families spend more than a specific percentage of their income on

groceries. What is that percentage of income value?