1. The following MINITAB output shows the time spent per week on line for 30 Internet users as well as the mean of the 30 times. Would you say this average is typical of the 30 times?
MTB > print cl
Data Display
3
|
4
|
4
|
5
|
5
|
5
|
5
|
5
|
5
|
5
|
6
|
6
|
6
|
7
|
7
|
7
|
7
|
7
|
8
|
8
|
9
|
10
|
10
|
10
|
10
|
10
|
10
|
10
|
55
|
60
|
MTB > mean cl
Column Mean
Mean of time = 10.400
2. Find the arithmetic mean of the numbers 5, 3, 6, 5, 4, 5, 2, 8, 6, 5, 4, 8, 3, 4, 5, 4, 8, 2, 5, and 4.
3. Out of 100 numbers, 20 were 4’s, 40 were 5’s, 30 were 6’s and the remainder were 7’s. Find the arithmetic mean of the numbers.
4. A student’s final grades in mathematics, physics, English and hygiene are, respectively, 82, 86, 90, and 70. If the respective credits received for these courses are 3, 5, 3, and 1, determine an appropriate average grade.
5. In a company having 80 employees, 60 earn $10.00 per hour and 20 earn $13.00 per hour.
(a) Determine the mean earnings per hour.
(b) Would the answer in part (a) be the same if the 60 employees earn a mean hourly wage of $10.00 per hour? Prove your answer.
(c) Do you believe the mean hourly wage to be typical?
6. Four groups of students, consisting of 15, 20, 10, and 18 individuals, reported mean weights of
162, 148, 153, and 140 pounds (lb), respectively. Find the mean weight of all the students.