Calculating Probability with Normal Distribution/ZScores

If this is the graph of data normally distributed with a mean of 30 and a standard deviation of 5, what label (number) is written at the blue circle?

If this is the graph of data normally distributed with a mean of 30 and a standard deviation of 5, what label (number) is written at the blue circle?

The normal curve is symmetrical about the mean.

• True
• False

What shape is a normal distribution curve?

• Half curve
• Round curve
• Bell curve
• Square curve

According to the empirical rule, how much of the data falls within 2 standard deviations of the mean?

According to the empirical rule, what percentage of data falls within 1 standard deviation of the mean?

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days.

About what percent of the products last between 12 and 15 days?

Find the Z-score.

Mean = 22

Standard Deviation: 3.1

x = 29

• 2.26

• 16.45

• -2.26

• 1.26

Find the Z-score.

Mean = 21

Standard Deviation: 1.3

x = 22

• 0.77

• 5.33

• 1.07

• 1.26

Find the Z-score.

Mean = 27

Standard Deviation: 1.4

x = 11

• -11.43

• 7.85

• -2.33

• 4.16