MathStories.comTM
Copyright © 1999-2001 MathStories.com, Inc, 1426 Pine Grove Way, San Jose, California 95129 . All Rights Reserved.

Sheet # 91 Critical Thinking

Name: _____________________ Date_____________


Use drawings, words, or numbers to explain how you got your answer.

Two brands of lights bulbs were tested. The lives, in hours, of 8 bulbs of each brand are listed below. On the basis of these tests, which bulb is better?

Brand A: 950, 967, 835, 1214, 1130, 891, 1070, 998

Brand B: 1015, 898, 1147, 935, 946, 893, 1235, 842








































Answers for sheet # 91

Calculate the average for each brand bulb.

Average of Brand A: (
950 + 967 + 835 +1214 + 1130 + 891 +1070 + 998)/8

1006 hours

Average of Brand B: 988 hours


Brand A is superior to Brand B



























Answer for sheet # 90

Let C is the capacity of the tank.

Half full means = C/2

(C/2) + 9 = (7/8) x C

4C + 72 = 7C

3C = 72

C = 24 gallons