Describing Location in a Distribution

What is the formula to find the z-score?

• z=value - mean

• z=(SD-mean)/value

• ^z/x=mean

• z=(value - mean)/SD

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

What is the shape of the distribution?

• Skewed Left 

• Skewed Right

• Symmetric

• Bimodal

If I tell you that you scored at the 55th percentile on your final exam, you would know:

• 55% of the class scored the same or worse than you did

• You earned a 55% on the exam

• You failed the exam

• 45% of the class scored worse than you did

Given the data set: 1, 2, 3, 6, 9, 11, 45, 102, calculate the percentile for the data value 11 in this set.

• 70^th percentile

• 62.5^th percentile

• 72.5^th percentile

• 75^th percentile

Find the percentile for the Mariners who won 69 games.

• 6th

• 20th

• 23rd

• 21st

The Washington National's number of wins puts them in the 70th percentile. How many wins does that represent?

• 21

• 91

• 95

• 89

A data set has a mean of 290 and a standard deviation of 20. Calculate the z-score for 265.