Statistics Review

Determine the range of the following test scores.

History Test 1 Scores (out of 100)

90 84 77 66

89 84 77 65

86 82 75 65

86 81 72 61

84 79 70 56

• 90

• 34

• 56

• 78

Environment Canada compiled data on the number of lightning strikes per square kilometre in Saskatchewan and Manitoba towns from 1999 to 2008.

2.03 1.31 0.25 1.03 1.20 0.17

0.99 1.01 0.24 0.94 0.92 0.09

0.86 0.71 0.05 0.81 0.63 0.01

0.80 0.58 0.00 0.72 0.49 0.52

0.43 0.46 0.40

Determine the standard deviation, to two decimal places.

• 0.45

• 0.25

• 0.65

• 0.05

A set of data is normally distributed. What percent of the data is within one standard deviation of the mean?

• about 95%

• about 50%

• about 68%

• 100%

A set of data is normally distributed. What percent of the data is within two standard deviation of the mean?

• about 68%

• 100%

• about 50%

• about 95%

A set of data is normally distributed. What percent of the data is greater than the mean?

• about 95%

• 100%

• about 68%

• about 50%

The ages of participants in a Halloween party are normally distributed, with a mean of 30 and a standard deviation of 10 years. What percent of the participants are between 30 and 40?

• 95%

• 34%

• 16%

• 68%

The ages of participants in a Halloween party are normally distributed, with a mean of 30 and a standard deviation of 10 years. What percent of the participants are between 10 and 20?

• 17.5%

• 13.5%

• 27%

• 32%

The ages of participants in a Halloween party are normally distributed, with a mean of 30 and a standard deviation of 10 years. What percent of the participants are between 20 and 40?

• 50%

• 20%

• 68%

• 34%

The ages of participants in a Halloween party are normally distributed, with a mean of 30 and a standard deviation of 10 years. What percent of the participants are older than 50?

• 1.25%

• 2.5%

• 0%

• 5%

A teacher is analyzing the class results for a physics test. The marks are normally distributed with a mean (µ) of 76 and a standard deviation (Sx) of 4.

Determine Shondra’s mark if she scored µ + Sx.

• 80

• 68

• 84

• 72