Exam 4: Measures of Dispersion

According to the data presented in the text,incomes in the U.S.are

The average deviation (AD)is

The information below compares the final exam grades for 2 biology classes: Class 1 Class 2 =80.2 =81.3 =12.1 =6.7 =25 =23 What may we conclude? Class 1

The expression $\mathrm { S } \left( \mathrm { X } _ { \mathrm { i } } - \bar { X } \right.$ )² instructs us to

Your score on the test is the same as the third quartile (Q₃).You may conclude that

For variables measured at the nominal level,an appropriate measure of dispersion is

As a distribution of scores becomes more variable,the value of the standard deviation

When you subtract the value of the mean from each score in a distribution and then add the results,the sum will be

The scores below are from the same final exam given in a math class in two different years.Compute the mean and median (if necessary)and the range and standard deviation of these scores.Using these statistics,describe the differences in the two sets of scores. $\text { This year }$ 35 45 65 75 87 80 169 71 53 90 99 95 70 82 73 93 67 61 57 74 72 77 71 81 83 $\text { Ten years }$ $\text { ago }$ 56 77 75 76 59 74 51 89 55 79 67 77 69 90 68 90 65 79 69 79 87 186 98 91 95

The greater the skew of a distribution of scores,

Measures of dispersion provide information about the

The age of a sample has been measured in years.Which of the following would be the preferred measure the dispersion for this variable?