Standard Deviation

Practice Problem 1:

The graph represents a distribution of data.

What is the mean of the data?

Practice Problem 2:

The graph shows a distribution of data with a standard deviation of 6.

Which statement is true about the data point 84?

• It is within 1 standard deviation of the mean.

• It is within 2 standard deviations of the mean.

• It is exactly 3 standard deviations from the mean.

• It is exactly 4 standard deviations from the mean.

Practice Problem 3:

The graph shows a distribution of data.

Which statement about the data is true?

• The data has a standard deviation of 0.1.

• The mean of the data is greater than 0.5.

• A value of 0.7 is within 1 standard deviation of the mean.

• A value of 0.9 is more than 2 standard deviations from the mean.

Tags

NGSS.HS-LS3-3

Practice Problem 4:

The mean score on a physics test was 75 points. Amy’s score was 67 points, which was 2 standard deviations below the mean.

What is the variance of the data set?

Bryant collects a set of 20 values that represent the lengths of worms he found in the garden. The variance of the set of values  is 36.

What is the standard deviation from the mean? Round the answer to the nearest tenth if necessary.

The mean shoe size of the students in a math class is 7.5. Most of the shoe sizes fall within 1 standard deviation, or between a size 6 and a size 9.

What is the standard deviation of the shoe size data for the math class?

Grace is looking at a report of her monthly cell-phone usage for the last year to determine if she needs to upgrade her plan. The list represents the approximate number of megabytes of data Grace used each month.

700, 735, 680, 890, 755, 740, 670, 785, 805, 1050, 820, 750

What is the standard deviation of the data? Round to the nearest whole number.

Raquel and Van live in two different cities. As part of a project, they each record the lowest prices for a gallon of gas at gas stations around their cities on the same day. Raquel’s data show x̅ = 3.42 and σ = 0.07. Van’s data show x̅ = 3.78 and σ = 0.23 .

Which statement is true about their gas-price data?

• Raquel’s data are most likely closer to $3.42 than Van’s data are to $3.78.

• Van’s data are most likely closer to $3.42 than Raquel’s data are to $3.78.

• Raquel’s data are most likely closer to $3.78 than Van’s data are to $3.42.

• Van’s data are most likely closer to $3.78 than Raquel’s data are to $3.42.

Which histogram represents a set of data that is left-skewed?

• 
• 
• 
• 

The histogram shows a city’s daily high temperatures recorded for four weeks.

Which phrase describes the shape of the temperature data?

• symmetrical

• left-skewed

• right-skewed

• normal

Tags

NGSS.HS-LS3-3