Day 14: Z-scores

What is the z-score for a data value that is below the mean by 2 standard deviations?

• +2.00

• -2.00

• +1.25

• -1.00

What is the z-score for a data value that is above the mean by 1/2 a standard deviation?

• -0.50

• +1.00

• +0.50

• -1.00

z-scores are the standardized scores for any data that is Normal.

• True

• Sometimes true, sometimes false

• False

The mean of the z-score will always be zero regardless of the original data values' range.

• True

• Sometimes true, sometimes false

• False

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

• True

• Sometimes true, sometimes false

• False

Jake took the ACT and Marlena took the SAT. Jake's z-score was 1.2 and Marlena's z-score was 1.4. Who did better on their test?

• Jake

• Marlena

• They did the same.

• It depends on the test.

Use the formula to find the Z-score.

Mean = 50

Standard Deviation: 10

x = 54

• 0.4

• -0.4

• 49

• 0

If a z-score is positive, that means the value is ABOVE the mean.

• True

• Sometimes true, sometimes false

• False

If a z-score is negative, that means the data value falls BELOW the mean.

• True

• Sometimes true, sometimes false

• False

Use the formula to find the Z-score.

Mean = 27

Standard Deviation = 1.4

x = 11

• -11.43

• 7.85

• -2.33

• 4.16