Example 5.51 from Prealgebra, 5.5 Averages and Probability

Averages and Probability: example 5.51

For the past four months, Daisy’s cell phone bills were $$42.75, $50.12, $41.54, $48.15 .$ Find the mean cost of Daisy’s cell phone bills.

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Your turn

The book's Try It right after this example: same idea, new numbers. Only the answer is given.

Last week Ray recorded how much he spent for lunch each workday. He spent $$6.50, $7.25, $4.90, $5.30, and $12.00 .$ Find the mean of how much he spent each day.

How did it go?

Write the formula for the mean.	$mean = \frac{sum of all the numbers}{n}$
Count how many numbers are in the set. Call this $n$ and write it in the denominator.	$mean = \frac{sum of all the numbers}{4}$
Write the sum of all the numbers in the numerator.	$mean = \frac{42.75 + 50.12 + 41.54 + 48.15}{4}$
Simplify the fraction.	$mean = \frac{182.56}{4}$
	$mean = 45.64$

Write the formula for the mean.	$mean = \frac{sum of all the numbers}{n}$
Count how many numbers are in the set. Call this $n$ and write it in the denominator.	$mean = \frac{sum of all the numbers}{4}$
Write the sum of all the numbers in the numerator.	$mean = \frac{42.75 + 50.12 + 41.54 + 48.15}{4}$
Simplify the fraction.	$mean = \frac{182.56}{4}$
	$mean = 45.64$

Averages and Probability: example 5.51

Solution

Your turn

Averages and Probability: example 5.51

Solution

Your turn