A vertical line drawn through a normal distribution at z = –1.00 separates the distribution into two sections, the body and the tail. What proportion of the distribution is in the body?

There exist tables of cumulative probabilities that hod the information corresponding to the standard normal distribution. Since the mean of the distribution is zero, there are two tables for this distribution, one called left-entry or left Z-table shows the corresponding cumulative probabilities for negative values of Z and the other called right entry or right Z-table show the corresponding cumulative probabilities for positive values of Z.

For both entries, the first column shows the integer and first decimal number of the Z-value and the first row shows the second decimal value, while the probabilities are in the body of the table.

The area below -1 corresponds to the "tail" and the area above it corresponds to the "body" of the distribution (see 1st attachment)

Symbolically:

Tail: P(Z≤-1.00)= 0.1587

Body: P(Z>-1.00)= 1-P(Z≤-1.00)= 1 - 0.1587= 0.8413

The proportion of the distribution that is in the body is 84.13%

I hope it helps!