Percents Normal Distribution

What percent of people within 1 standard deviation of the mean?

• 99.7

• 34

• 68

• 95

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days. One company warns that because of the "freshness" of their ingredients, their products only have a shelf life of 5 days. What percentile is this? What percent of products have a longer shelf life?

• 1st percentile, 99%

• 99th percentile, 1%

According to the empirical rule, what percentage of data falls within 1 standard deviation? 

• 25%

• 68%

• 95%

• 99.7%

The Empirical Rule's percents are:

• 68-95.7-99

• 68-95-99.7

• 68.7-95-99

Find the z score with x% of data above it.

• normalCDF

• invNorm

• z score formula

InvNorm always uses the area __________ the given score.

• above

• below

In a factory, the weight of the concrete poured into a mold by a machine follows a normal distribution with a mean of 1150 pounds and a standard deviation of 22 pounds. What is the z-score for 1200 pounds?

• z=2.27

• z-=23.27

• z=-2.27

• z=-23.27

68% of the data lies within:

• 3 Standard Deviations of the Mean

• 2 Standard Deviations of the Mean

• 1 Standard Deviation of the Mean

95% of the data lies within:

• 3 Standard Deviations of the Mean

• 2 Standard Deviations of the Mean

• 1 Standard Deviation of the Mean

99.7% of the data lies within:

• 3 Standard Deviations of the Mean

• 2 Standard Deviations of the Mean

• 1 Standard Deviation of the Mean