Big Ideas Math Integrated I, 2016
BI
Big Ideas Math Integrated I, 2016 View details
4. Solving Absolute Value Equations
Continue to next subchapter

Exercise 60 Page 34

Practice makes perfect
a Let's take a look at the circle graph.

Looking at the graph, we can see that 42 % voted Republican and 2 % voted Green Party. However, taking the margin of error into account, these numbers could either be 2 % lower or 2 % greater. &Republican &Minimum: 40 % - 2 % =38 % &Maximum: 40 % + 2 % =42 % [1em] &Green Party &Minimum: 2 % - 2 % =0 % &Maximum: 2 % + 2 % =4 % [1em]

b The difference between the reported percent and the minimum and maximum percents is -2 and 2, respectively. In both cases the absolute value of these differences is 2.

|-2|= 2=|2| Using the reported percents as our midpoints, we can write the following absolute value equations to describe the result of the survey for the Republican and Green Party candidate. Republican:& |x- 42|= 2 Green Party:& |x- 2|= 2 Those equations tell us that the actual results could be 2 more or 2 less than their respective midpoints.

c As we already determined, 44 % falls within the margin of error for the Republican candidate.

Republican Margin: 42 ± 2 % The only other candidate with votes that come close to 44 % is the Democratic candidate. Let's calculate the minimum percent of votes the Democratic candidate could receive. 47 %- 2 %=45 %. Since the minimum percent of votes the Democratic candidate could receive is greater than 44 %, the candidate who received 44 % must be Republican.