
Concept explainers
a.
Find a linear model for the data.
a.

Answer to Problem 82RE
The linear equation is y=240.58t−10.877
Explanation of Solution
Given information:
The table shows the sales y (in millions of dollars) for Aéropostale, Increase from 2003 through 2010 .
Use the regression feature of a graphing utility to find a linear model for the data. Let t represent the year, with t=3 corresponding to 2003 .
Calculation:
Enter the data in calculator.
Press button STAT and select EDIT and press enter.
Enter year in L1 and salary in L2 .
To find the linear function use regression in calculator, press STAT ans select CAL then press enter, the linear equation is y=240.58t−10.877
Hence, the linear equation is y=240.58t−10.877
b.
Find the area of the trapezoid bounded by the linear model.
b.

Answer to Problem 82RE
Explanation of Solution
Given information:
The table shows the sales y (in millions of dollars) for Aéropostale, Increase from 2003 through 2010 .
The total sales for Aéropostale during this eight-year period can be approximated by finding the area of the trapezoid bounded by the linear model you found in part (a) and the lines y=0 , t=2.5 and t=10.5 Use the graphing utility to graph this region.
Calculation:
Area bounded by y=0 , t=2.5 and t=10.5 is shown as,
c.
Find the area of the trapezoid bounded by the linear model.
c.

Answer to Problem 82RE
the total sale is $7698.8million
Explanation of Solution
Given information:
The table shows the sales y (in millions of dollars) for Aéropostale, Increase from 2003 through 2010 .
Use the formula for the area of a trapezoid to approximate the total sales for Aéropostale. Calculation:
We know that,
y=240.58t−10.877y(2.5)=240.58×2.5−10.877=590.59y(10.5)=240.58×10.5−10.877=2515.29
Area of a trapezoid is,
Area= 12 (sum of length of parallel sides) (distance between them)
Area=12(2515.29−590.59)(10.5−2.5)=962.35×8=7698.8
Hence, the total sale is $7698.8million
Chapter 7 Solutions
EBK PRECALCULUS W/LIMITS
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