Normal Distribution Vocabulary

In a normal distribution, approximately ______% of the data items fall within 1 standard deviation of the mean.

• 50

• 68

• 95

• 99.7

In a normal distribution, approximately ______% of the data items fall within 2 standard deviation of the mean.

• 68

• 75

• 95

• 99.7

In a normal distribution, approximately ______% of the data items fall within 3 standard deviation of the mean.

• 68

• 75

• 95

• 99.7

A z-score describes how many standard deviations a data item in a normal distribution lies above or below the _________?

• median

• mode

• mean

• middle

If n% of the items in a distribution are less than a particular data item, we say that the data item is in the nth ________ of the distribution.

• quartile

• percentile

• range

• mode

The mean, median, and mode or a normal distribution are all equal.

• True

• False

In a normal distribution, the z-score for the mean is 0.

• True

• False

The z-score for a data item in a normal distribution is obtained using z-score = (data item - standard deviation)/mean.

• True

• False

A score in the 50th percentile on a standardized test is the median

• True

• False