Download 3

name:
Mathematics 146 third homework
due Friday, October 9 , 2015
please show your work to get full credit for each problem
1. A very small population of test scores consists of 5 data values:
100
90
80
70
70
(a) compute the median M , the mean µ, and the midrange of the test scores.
(b) compute the M.A.D. (median absolute
and the range of the test scores.
deviation from the median),
the standard deviation σ,
(c) what percent of the test scores are within one standard deviation of the mean ? within
two standard deviations of the mean ?
2. Suppose a related data set has a very low “outlier” test score:
100
90
80
70
10
Redo parts (a), (b), and (c) of problem one with this new data set to see how much the
various measurements of center and dispersion change with the “outlier.”
3. Using the annual incomes in a certain area from the previous homework
income in thousands of $
10, 000
80
40
20
relative frequency
1%
9%
47%
43 %
(a) calculate the standard deviation of the annual incomes (it’s a weighted average !)
(b) what percentage of the incomes are within one standard deviation of the mean ? within
two standard deviations of the mean ?