The mean of a normal probability distribution is 500 and the standard deviation is 10. about 95 percent of the observations lie between what two values?

So about 95 percent of the observations lie between 480 and 520.

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviations of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

The mean is 500 and the standard deviation is 10.

About 95 percent of the observations lie between what two values?

From the Empirical Rule, this is from 500 - 2*10 = 480 to 500 + 2*10 = 520.

So about 95 percent of the observations lie between 480 and 520.

the correct answer is the second option