Standard Deviation Worksheet
Name:
1. Find the mean, the variance and the standard deviation for the data.
{18, 18, 19, 18, 18, 25, 29, 30, 26, 19}
2.
A biologist is growing bacteria in the lab. For a certain species of bacteria, she records these doubling times: 41
min, 45 min, 39 min, 42 min, 38 min, 88 min, 43 min, 40 min, 44 min, 39 min, 42 min, and 40 min.
a. Find the mean.
b. Find the standard deviation.
c. Identify any outliers.
d. Describe how any outlier affects the mean and the standard deviation.
3.
The 2004 Cincinnati Bengals scored 24, 16, 9, 17, 17, 23, 20, 26, 17, 14, 58, 27, and 28 points in their first 13
games. Find the mean and the standard deviation of the data. Identify the outlier, and describe how it affects
the mean and the standard deviation.
Use the rule Q1 – 1.5(IQR) or Q3 + 1.5(IQR) to identify any outliers in each data set. Show your work.
4. {2, 3, 4, 5, 5, 25}
5. {91, 90, 79, 15, 82, 90, 88}
6. {1, 36, 34, 33, 35, 92}