bell-shaped distribution

Question

The mean price of new homes from a sample of houses is $155,000 with a standard deviation of $15,000.

The data set has a bell-shaped distribution.

Between what two prices do 95% of the houses fall?

Between what two prices do 99.7% of the houses fall?

Find each of the following percentiles:

A $191,000 new home is randomly selected. Find its corresponding z-score and determine if it is unusual.

Round your z-score to two decimal

Answer 1

This is the 68-95-99.7 rule - Learn it!

95% are between 2 s.d. below and 2 s.d. above the mean

99.7% are between 3 s.d. below and 3 s.d. above the mean