Normal Distribution and Empirical Rule and Z-Score

Find the z-score for 48 given a mean of 50 and a standard deviation of 5.

• 2.5

• -2.5

• -0.4

• 0.4

Find the z-score for 258 given a mean of 273 and a standard deviation of 5.

• 3

• -2

• 2

• -3

Find the area under the standard normal curve that lies to the right of z=-0.67.

• 63.42%

• 74.86%

• 25.14%

• 50%

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?

• 20

• 15

• 40

• 30

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?

(Remember to draw a curve with the values to help you.)

• 68%

• 34%

• 16%

• 2.5%

Find the area under the standard normal curve that lies between z=-0.5 and z=1.5.

• 62.46%

• 72.47%

• 5.40%

• 62.47%

IQ tests have a mean of 100 and SD of 16. Einstein's IQ was 160. What is the z-score of his IQ?

• 1.75

• 3.75

• 0.75

• 2.75

Z-score of 2.5 on an IQ test is considered a genius (mean=100, SD=16). What score makes someone a genius? Hint: SOLVE for X

• 89.2

• 130

• 99.38

• 140

List each set of data by color from the lowest standard deviation to the highest standard deviation.

• blue, green, pink, red

• red, pink, green, blue

• pink, green, red, blue

• blue, green, red, pink

The z-table gives the percent of data at or below a z-score.

• True

• Sometimes true, sometimes false

• False