Alg 2 Measures of Center CW5
Name______________________Pd________
1. Working alone, John can dig a 10 ft by 10 ft hole in 13 hours. Fred can dig the same hole
in 10 hours. How long would it take them if they worked together?
2. Jack has taken 4 tests in his math class, with grades of 56, 82, 63, and 86. In order to
maintain this exact average, what must be his grade on his 5th math test?
3. Bruce has taken 5 tests in his math class, with grades of 70, 83, 61, 84, and 80. In order to
maintain this exact average, what must be his grade on the next test?
4. The average of 7 numbers is 25.8. If each of the numbers is decreased by 12, what is the
average of the 7 new numbers?
5. The average of 15 numbers is 34. If each of the numbers is decreased by 17.2, what is the
average of the 15 new numbers?
6. A student’s grades on the first 5 tests were 56, 70, 68, 62, and 88. How many points must
the student recieve on the next test to average exactly 72 points (assume that all tests are
weighted equally)?
7. What is the median of the data given below?
48, 62, 71, 36, 22, 36, 51, 26, 62, 37
8. A student’s test average after 7 tests was 77. The score on the 8th test was 97. If all 8
tests were equally weighted, which of the following is closest to the test average after 8
tests?
9. A student’s test average after 3 tests was 92. His score on the 4th test was 60. If all tests
were equally weighted, which of the following is closest to thetest average after 4 tests?
10. To decrease the mean of 21 numbers by 4, by how much would the sum of the 21
numbers have to decrease?
11. To increase the mean of 17 numbers by 6, by how much would the sum of the 17
numbers have to increase?
12. The average (arithmetic mean) of 12 numbers is x. If one of the numbers is y, what is the
average of the remaining numbers in terms of x and y?
13. If t = j + k, what is the average (arithmetic mean) of j and k in terms of t?
14. A group of students take a test and the average score is 72. One more student takes the
test and receives a score of 66 changing the average score of the group to 70. How many
students were in the initial group?
15. Stan has performed 7 repairs on his car averaging $326 for each repair. Stan’ goal was
to not spend more than $2700 on this old car. By how much is Stan under his budget?
16. The store sold 36 shirts on Tuesday and 43 shirts on Thursday. The total cost on
Tuesday was $822 and the total cost on Thursday was $937. What was the average cost
of one of the shirts sold on Tuesday? What was the average cost of one shirt on
Thursday?