Question

A set of 1000 values has a normal distribution. The mean of the data is 120, and the standard deviation is 20. How many values are in one standard deviation from the mean?

Answer 1

There are 800 values within one standard deviation from the mean.

Step-by-step explanation:

To find how many values are in one standard deviation from the mean, we need to determine the range within one standard deviation of the mean. In a normal distribution, approximately 68% of the values fall within one standard deviation of the mean.

We can calculate this by subtracting one standard deviation from the mean and adding one standard deviation to the mean. So, in this case, the range within one standard deviation of the mean is 120 - 20 to 120 + 20, which is 100 to 140.

Therefore, there are 1000 - (100 + 100) = 800 values that are within one standard deviation from the mean.