Parking meters in a beach resort town cost $25¢$ for $15$ minutes. A normal distribution with a mean of $\$10$ and a standard deviation of $\$2$ can be used to model the amount of money one parking meter makes on a busy summer day. .

1. Make a graph of the distribution of the money made by one meter on your calculator, and sketch it. An appropriate value for the maximum of the relative frequency axis is Ymax $= 0.2$.

2. From your graph, visually estimate where the middle $90\%$ of meter earnings fall. Shade this portion of your sketch.

3. Use your calculator to check your estimate. How close to $90\%$ did you come?

   Hint (c):

   normalcdf(lower estimate, upper estimate, $10, 2$) $= 0.90$

   Use the eTool below to help solve parts (a - c).
   Click the link at right for the full eTool version: CCA2 10-152 HW eTool