Question

Use the following table to answer each question.

Using sigma notation find the mean water bill for the entire year. Round your answer to the nearest cent.

Using sigma notation find the mean water bill for the first 6 months of the year. Round your answer to the nearest cent.

Using sigma notation find the mean water bill from April through November. Round your answer to the nearest cent.

Answer 1

• $47.33
• $43
• $50.25

Explanation:

Using table calculating the mean for each case

1. Entire year, sample size 12

• x = 1/12* ∑ xi, i= 1 to 12
• x = 1/12(40+42+40+38+48+50+58+62+56+46+44+44)
• x = 1/12*568 = $47.33

2. First six months, sample size 6

• x = 1/6*∑ xi, i= 1 to 6
• x = 1/6(40+42+40+38+48+50)
• x = 1/6*258 = $43

3. April through November, sample size 8

• x = 1/8*∑ xi, i= 4 to 11
• x = 1/8(38+48+50+58+62+56+46+44)
• x = 1/8*402 = $50.25