Statistics High School

The mean of a data set is 20, and the standard deviation is 5. What is the z-score of a data point that is 25?

• 1

• 5

• 0

• -1

Calculate the variance of the data set: 2, 4, 4, 4, 5, 5, 7, 9.

• 4

• 2

• 3

• 5

The standard deviation of a dataset is 4. If each data point in the dataset is multiplied by 2, what is the new standard deviation?

• 2

• 4

• 8

• 16

Which set of data could be represented by the given box-and-whisker plot?

• 72, 72, 78, 80, 78, 76, 76, 76

• 80, 80, 78, 72, 76, 71, 76, 76

• 79, 76, 76, 78, 72, 79, 80, 72

• 78, 72, 78, 76, 76, 72, 76, 81

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The box plot below shows the weight in grams of pick and mix sweets at a cinema. What proportion of the bags weigh more than 95 g?

• 20%

• 25%

• 50%

• 75%

Using the given double box-and-whisker plot, determine the percent of the boys and then the percent of the girls who are 66 inches or shorter.

• 25%, 75%

• 75%, 25%

• 50%, 75%

• 50%, 25%

The percentile represents the....

• percent of data values that are below.

• percent of data values that are above.

• number of data values that are below.

• number of data values that are below.

Chloe counted the number of cars that were parked on her road at 8:00 pm on 11 successive days. She presented her data as a list: 3, 8, 12, 6, 5, 6, 7, 9, 4, 10, 8.

She was surprised to find that the minimum number of cars that she counted was 3 and that the maximum number of cars was 12.

Chloe draws a box plot of the data. Which of the following is correct?

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• 
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• 
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What percentage of days was the temperature between 22∘C and 24∘C?

(Leave out the % in your answer)