Standard Deviation and Variance

Question

Since the start of the Obama presidency, the average number of minutes playing golf each week is 160 minutes and the standard deviation is 20 minutes. The average number of minutes attending cabinet meeting per week is 6 minutes and the standard deviation is 15 minutes. What is more variable golf minutes or cabinet meeting minutes?

Please show work. Thank you.

It depends upon "more variable" means in the absolute sense of number of minutes or in the relative sense of fraction of the number of minutes. — Ross Millikan, Feb 11 '13 at 23:32

score 2 · Accepted Answer · answered Feb 11 '13 at 23:26

2

Try putting the comparison in a ratio: $\dfrac{\text{standard deviation in minutes}}{\text{average time of ____ in minutes}},\;$ in terms of golf, and then in terms of cabinet meetings.

Then simplify and compare the two ratios. Which is larger than the other?

The larger of the two will correspond to which is the most variable: golf minutes vs. cabinet minutes.

answered Feb 11 '13 at 23:26

amWhy

209,954

Let me know what you can conclude, and I'll confirm or correct you. – amWhy Feb 11 '13 at 23:30
I got .125 for golf and .4 for cabinet minutes. So the cabinet minutes is more variable? – Shaily Feb 11 '13 at 23:34
Absolutely, yes, the time spent in cabinet minutes is much more variable! Does that make sense? – amWhy Feb 11 '13 at 23:36
Yes it does. Thank you – Shaily Feb 11 '13 at 23:37
You're welcome! – amWhy Feb 11 '13 at 23:37

Standard Deviation and Variance

1 Answers1