Author Question: House calls A local plumber makes house calls. She charges 30 to come out to the house and 40 per ... (Read 490 times)

Yolanda · **on:** Jul 25, 2018

House calls A local plumber makes house calls. She charges 30 to come out to the house and 40 per hour for her services. For example, a 4-hour service call costs 30 + 40(4 ) = 190.

a. The table shows summary statistics for the past month. Fill in the table to find out the cost of the service calls.
Statistic Hours of Service Call Cost of Service Call
Mean 4.5
Median 3.5
SD 1.2
IQR 2.0
Minimum 0.5
b. This past month, the time the plumber spent on one service call corresponded to a z-score of -1.50. What was the z-score for the cost of that service call?

Question 2

Cats and dogs The table shows whether students in an introductory statistics class like dogs and/or cats.

Like Dogs
Yes No Total
Like Cats Yes 194 21 215
No 110 10 120
Total 304 31 335
a. What is the marginal distribution (in ) of liking dogs?
b. What is the conditional distribution (in ) of liking dogs for students who like cats?
c. What kind of display(s) would you use to examine the association between liking dogs and liking cats? (Just name a graph.)
d. Do liking dogs and liking cats appear to be independent? Give statistical evidence to support your conclusion.

bubulittle310@msn.cn · **Reply #1 on:** Jul 25, 2018

Answer to Question 1

a.
Statistic Hours of Service Call Cost of Service Call
Mean 4.5 210
Median 3.5 170
SD 1.2 48
IQR 2.0 80
Minimum 0.5 50

b. -1.50

Answer to Question 2

a. Yes: 90.7 No: 9.3
b. Yes: 90.2 No: 9.8
c. segmented bar graph or pie charts
d. Perhaps. There is little difference between the percents of those who like dogs, depending on whether they like cats. Of those who like cats, only 90.2 like dogs, compared to 90.7 overall.