The SPCA has kept these data records for the past 20 years. If they want to show the trend in the number of dogs they have housed, what kind of plot should they make?
A) pie chart B) bar graph C) boxplot D) timeplot E) histogram
Q. 2Which of those variables about German Shepherds is most likely to be described by a Normal model?
A) number of days housed
B) veterinary costs
C) age
D) breed
E) weight
Q. 3The SPCA collects the following data about the dogs they house. Which is categorical?
A) weight
B) number of days housed
C) breed
D) veterinary costs
E) age
Q. 4Soda cans A machine that fills cans with soda fills according to a Normal model with mean 12.1 ounces and standard deviation 0.05 ounces.
a. If the cans claim to have 12 ounces of soda each, what percent of cans are under-filled?
b. Management wants to ensure that only 1 of cans are under-filled.
i. Scenario 1: If the mean fill of the cans remains at 12.1 ounces, what standard deviation does the filling machine need to have to achieve this goal?
ii. Scenario 2: If the standard deviation is to remain at 0.05 ounces, what mean does the filling machine need to have to achieve this goal?
Q. 5House 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?
Q. 6Cats 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.
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