The document discusses how to find a specific portion of a population from a normal distribution with a mean of 100 and a standard deviation of 10. It requires the use of a z-table and emphasizes the need to show the work and formulas used in the calculations. The main goal is to calculate the probability of the population being less than or equal to a certain value, specifically 80.

1. A Normal distribution with mean 100 and standard deviation equal to 10 using the Z table below.
MUST SHOW WORK and formulas used step by step. thanks
The portion of the population P(80