11.10 Day 4 Warmup

Find the z-score.

Mean = 38

Standard Deviation: 1.2

x = 42

• 3.33

• -3

• 3.03

• -3.33

Find the z-score.

Mean: 22.8

Standard Deviation: 7

x = 20

• -0.4

• 17.2

• 22.04

• 32.5

What is the purpose of z-scores?

• to describe the exact location of a score within a distribution

• to find the mean of the distribution

• to describe the shape of the distribution

• to find the standard deviation of the distribution

The sign of the z-score indicates whether the location is above(positive) or below(negative) the mean.

• True

• False

Find the z-score value corresponding if the location is below the mean by 2 standard deviations

• +2.00

• -2.00

• +1.25

• -1.00

Find the z-scores value corresponding if the location is above the mean by 1/2 standard deviations

• -0.50

• +1.00

• +0.50

• -1.00

The mean of the z-score will always be zero even though the raw scores is 100

• True

• False

The distribution of z-scores will always have a standard deviation of 1

• True

• False

A data set has a mean of 300 and a standard deviation of 40. What value would have a z-score of  $z=-2$  ?

• 298

• 296

• 220

• 380

Steve took his math test and scored an 88. If the class average was a 78 with a standard deviation of 5, what percent of students earned a grade that was higher than Steve's grade?

• 97.5%

• 93%

• 5%

• 2.5%