Question 3 (4 marks)

Random samples of households were selected from each of three regions in

a large metropolitan area. The number of households selected from each

region and the corresponding mean household incomes are provided in the

table below.

Region-----Households Selected (Number)-------Mean Household Income

($1,000)

A 75 49

B 30 80

C 20 40

What is the mean household income for all three regions combined?

**Question 4 (4 marks) A course has two quizzes of equal weight, a midterm examination that has twice the weight of a quiz, and a final examination that has twice the weight of the midterm exam. If a student obtains 54% and 60% on the quizzes; 55% on the midterm; and 80% on the final, what will be the students weighted mean final grade?

Question 5.(5 marks) The mean amount spent by all customers at an organic food market is estimated to be $48, and the standard deviation is estimated to be $12. According to Chebyshevs Theorem, at least what percentage of customers would be expected to spend between $27 and $69? Note: Express your answer to two decimal places of accuracy