Standard Deviation

The weekly salaries of a sample of employees at the local bank are given in the table below. What is the variance for the data?

17507.5

The test scores of a geometry class are given below. 90, 75, 72, 88, 85 The teacher wants to find the variance for the class population. What is the value of the numerator of the calculation of the variance?

258

A missing data value from a set of data has a z-score of -2.1. Fred already calculated the mean and standard deviation to be mc025-1.jpg and mc025-2.jpg. What was the missing data value? Round the answer to the nearest whole number.

39

A poll worker analyzing the ages of voters found that mc024-1.jpg and mc024-2.jpg. What is a possible voter age that would give her zx = 1.14? Round your answer to the nearest whole number.

71

The mean of a set of credit scores is mc021-1.jpg and mc021-2.jpg. Which credit score is within a z-score of 3.3?

720

Which formula is used to calculate the standard deviation of sample data?

A

Fiona recorded the number of miles she biked each day last week as shown below. 4, 7, 4, 10, 5 The mean is given by m = 6. Which equation shows the variance for the number of miles Fiona biked last week?

D

The mean ages with standard deviations of four swim teams at a swim club are given below. Which statement is most likely to be true?

The ages of the Stars are the most dispersed from the team's mean.

A set of data has a mean of 12 and a standard deviation of 3. A data point of the set has a z-score of 1.3. What does a z-score of 1.3 mean?

The data point is 1.3 standard deviations away from 12.

A scientist collected two sample sets of snowfall data. Which statistic should he use to compare the spread of the two sets of data?

standard deviation

Mrs. Rodrigues wants to compare the spread of the test scores of her two biology classes. Which statistic should she use?

standard deviation

A set of data has a mean of 0.5 and a standard deviation of 0.01. A data point of the set has a z-score of 2.5. What does a z-score of 2.5 mean?

The data point is 2.5 standard deviations away from 0.5.