Question 899:

Asked on September 5, 2011

Tags: Standard Deviation , Variance

1

Answer:

No answer provided yet.We can see that the average age of the men was higher than the women by about four years. But we don't know how much this difference can be attributed to chance. To find out we need the standard deviation and sample size. We are only given the standard deviation and not the sample sizes in each group so we have to draw our conclusions from the standard deviations alone.

We can see that the standard deviation of the men was 156.91 and 116.16 for the women. Right away we can see that the men's ages fluctuate more (are more variable) than the women. To compare the variability of two groups we should use the variance instead of the standard deviation. The variance is just the standard deviation squared.

For the men the variance is 24620 and the women it is 13493. Now we can see that the men's ages are about 1.82 times more variable than the women. This means that the ages are both higher and lower (fluctuating more around the average) than women.