measures of central location and variation

Which of the following is referred to as the population mean?

• s

• x̄

• X

• µ

Which measure of central location can be applied to any level of measurement?

• Mode

• Median

• Mean

• Geometric mean

a sample of single persons receiving Social Security payments revealed these monthly benefits: $826, $699, $1,087, $880, $839, and $965. What is the median monthly benefit?

• $832.5

• $839

• 859.5

• $880

Which measures of central location are not affected by extremely small or large values?

• mode and mean

• median and mean

• median and mode

• standard deviation

When a dataset has two values that have the highest and equal frequencies, the distribution is:

• bimodal

• symmetric

• uni-modal

• skewed to the right

當平均數>中位數>眾數，此時資料分布是:

• 對稱

• 左偏

• U型

• 右偏

What is the shortcoming of "range" as a measure of dispersion?

• It is perfect, no shortcoming!

• it is difficult to interpret詮釋

• it can be 0

• based on only two values; not considering all of the values

The mean of the absolute differences between each value and the mean of the values is:

• Variance

• Standard Deviation

• Mean Absolute Deviation

• Range

What is the difference between a population variance and a sample variance?

• No difference, they are the same

• the denominator of the sample variance is n-1

• Sample variance is the square root of population variance

• the denominator of the sample variance is n