1990 AJHSME Problems/Problem 20
Revision as of 20:45, 11 July 2009 by 5849206328x (talk | contribs) (Created page with '==Problem== The annual incomes of <math>1,000</math> families range from <math>8200</math> dollars to <math>98,000</math> dollars. In error, the largest income was entered on t…')
Problem
The annual incomes of families range from dollars to dollars. In error, the largest income was entered on the computer as dollars. The difference between the mean of the incorrect data and the mean of the actual data is
Solution
Let be the sum of all the incomes but the largest one. For the actual data, the mean is , and for the incorrect data the mean is . The difference is .
See Also
1990 AJHSME (Problems • Answer Key • Resources) | ||
Preceded by Problem 19 |
Followed by Problem 21 | |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | ||
All AJHSME/AMC 8 Problems and Solutions |