Problem 1: (a) One wants to determine the average price per gallon of regular un
ID: 3133911 • Letter: P
Question
Problem 1:
(a) One wants to determine the average price per gallon of regular unleaded gas in town A. The prices for the seven gas stations in town A are determined. What is the population for this study? Is a statistical study appropriate?
(b) One wants to determine the average number of parts made per hour for all the hours in April 2016. Ten hours in April 2016 are randomly selected and the number of parts made determined for each of the ten hours. What is the population for this study? Is a statistical study appropriate?
(c) The resulting values in part (b) are below. Draw a stem-and-leaf display for this data. 39, 18, 30, 21, 39, 19, 33, 20, 31, 32
(d) Is the stem-and-leaf display in part (c) mound shaped?
Explanation / Answer
Problem 1:
(a) One wants to determine the average price per gallon of regular unleaded gas in town A. The prices for the seven gas stations in town A are determined. What is the population for this study? Is a statistical study appropriate?
Solution: The population for this study is considered as the prices per gallon of regular unleaded gas at all gas stations in the town A. This statistical study is inappropriate because the seven gas stations are not selected randomly for estimation of average price per gallon of regular unleaded gas in town A.
(b) One wants to determine the average number of parts made per hour for all the hours in April 2016. Ten hours in April 2016 are randomly selected and the number of parts made determined for each of the ten hours. What is the population for this study? Is a statistical study appropriate?
Solution: The population for this study is the number of parts made per hour for all the hours in April 2016. This statistical study is appropriate because ten hours in April 2016 are randomly selected.
(c) The resulting values in part (b) are below. Draw a stem-and-leaf display for this data. 39, 18, 30, 21, 39, 19, 33, 20, 31, 32
Solution: The stem and leaf display for the above data is given as below:
Number of parts
Stem
Leaf
18
1
8,9
19
2
0,1
20
3
0,1,2,3,9,9
21
30
31
32
33
39
39
(d) Is the stem-and-leaf display in part (c) mound shaped?
Solution: The stem and leaf display in part (c) is not a mound shaped.
Number of parts
Stem
Leaf
18
1
8,9
19
2
0,1
20
3
0,1,2,3,9,9
21
30
31
32
33
39
39