Find the indicated area under the curve of the standard normal​ distribution; then convert it to a percentage and fill in the blank. About​ % of the area is between z1 and z1 ​(or within 1 standard deviation of the​ mean). About 68 nothing​% of the area is between z1 and z1 ​(or within 1 standard deviation of the​ mean).

68% of the area

Step-by-step explanation:

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

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

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

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

In this question:

By the Empirical Rule, 68% of the area is within 1 standard deviation of the mean.

explanation:

previous steps have made pa≅ pb ≅ st ≅ su. setting the compass width to ab allows you to make tu the same length. then δstu ≅ δpab by the sss congruence postulate, and ∠p ≅ ∠s by the reason cpctc.