College Of The Canyons Math 140 Exam 1 Amy Morrow (Page 4 of 8) in pdf

College Of The Canyons Math 140 Exam 1 Amy Morrow Page 4

College of the Canyons

Math 140 Exam 1

Amy Morrow

(a) Which dealer oﬀers the cheapest car oﬀered?

(a)

Solution: Carz

(b) Which dealer has the lowest median price?

(b)

Solution: BuyIt

(c)

Solution: Ace

(d) Which dealer’s prices have the smallest IQR, and what is it? (2 points)

(d)

Solution: Carz,

4 or 5 thousand

(e) Which dealer generally sells cars the cheapest?

(e)

Solution: BuyIt

7. Light bulbs are measured in lumens (light output), watts (energy used), and hours (life). A standard

white light bulb has a mean life of 675 hours and a standard deviation of 50 hours. A soft white light

bulb has a mean life of 700 hours and a standard deviation of 35 hours. At a local science competition,

both light bulbs lasted 750 hours. Which light bulb’s life span was better? (Choose the best answer)

A. Relatively, the standard white light bulb performed better.

B. Relative to each other, the light bulbs performed the same.

C. Relatively, the soft white light bulb performed better.

D. There is no basis for comparison, since they are diﬀerent kinds of light bulbs.

E. There is not enough information for comparison.

8. A taxi company monitoring the safety of its cabs

kept track of the number of miles tires had been

driven (in thousands) and the depth of the tread

remaining (in mm). Their data are displayed in the

scatterplot. They found the equation of the least

squares regression line to be tread = 36

0.6miles,

with r = 0.74.

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College Of The Canyons Math 140 Exam 1 Amy Morrow Page 4