9514 1404 393
Explanation:
From your knowledge of the world, you know that ...
- the cost of multiple items is the sum of their individual costs
- multiplication can be used for repeated addition
- utility fees are the sum of fixed fees and usage-related fees
- for a phone plan, text message costs are a usage-related fee
The problem statement asks for the cost of a single text message. For the purpose of finding that value, it is convenient to represent it using the variable <em>t</em>. The problem statement says Eric was billed for 450 text messages, so we expect his usage-related fee to be 450t, the sum of the costs of 450 messages--using multiplication for the repeated sum.
The problem statement says Eric was billed 12.50 for fixed fees. So, we expect Eric's total bill to be ...
fixed fees + usage-related fees = 12.50 + 450t
The problem statement says Eric's total bill was 35.00, so we assume that is the sum of the above-listed fees. That is, the two ways to express Eric's total bill are equal.
12.50 +450t = 35.00
Steps Determine whether or not the fractions have the same denominator. This is the first step to comparing fractions. Find a common denominator. To be able to compare the fractions, you'll need to find a common denominator so you can figure out which fraction is greater. Change the numerators of the fractions.
Answer:
= −0.26
= 0.4219
Step-by-step explanation:
Given:
Sample1: 98.1 98.8 97.3 97.5 97.9
Sample2: 98.7 99.4 97.7 97.1 98.0
Sample 1 Sample 2 Difference d
98.1 98.7 -0.6
98.8 99.4 -0.6
97.3 97.7 -0.4
97.5 97.1 0.4
97.9 98.0 -0.1
To find:
Find the values of and
d overbar ( ) is the sample mean of the differences which is calculated by dividing the sum of all the values of difference d with the number of values i.e. n = 5
= ∑d/n
= (−0.6 −0.6 −0.4 +0.4 −0.1) / 5
= −1.3 / 5
= −0.26
s Subscript d is the sample standard deviation of the difference which is calculated as following:
= √∑(
- )²/ n-1
=
√ 
= √ (−0.6 − (−0.26
))² + (−0.6 − (−0.26))² + (−0.4 − (−0.26))² + (0.4 −
(−0.26))² + (−0.1 − (−0.26))² / 5−1
= 
= 
= 
= 0.4219
= 0.4219
Subscript d represent
μ
represents the mean of differences in body temperatures measured at 8 AM and at 12 AM of population.
Looks like the answer would be 219 people since you can't have half a person.
