Answer
$984$ pounds
Work Step by Step
A weight that is 2 standard deviations below the mean, that is, a weight with $z=-2$:
$z=\frac{y-\mu}{\rho}$
$y=\mu+z\times\rho=1152-2\times84=984$
The answer is a weight of $984$ pounds. Values that are more than $2$ standard deviations from the mean are considered unusual because they occur in less than $5\%$ of the cases in a normal distribution.
