Question

The graph shows a distribution of data with a standard deviation of 6.

Answer 1

The mean of the standard normal graph shown is the middle point about which the graph is symmetric.

Hence, mean is 75.

Also, given that standard deviation is 6.

What is 1 standard deviation from the "mean" mean?

75+6=81 and  75-6=69

So a value within 69 and 81 would be called within 1 standard deviation of the mean.

So, calculating 2 standard deviation from the mean as:

75+6+6=87 and 75-6-6=63

So a value within 63 and 87 would be called within 2 standard deviation of the mean.

84 falls in this category, so we can say answer choice B is correct.

ANSWER: B

Answer 2

B. It is within 2 standard deviations of the mean.