Iqr, Outliers, Standard Deviation, Mean, Median

The diagram shows a box-and-whisker plot of a set of data. The interquartile range of the data is 5.5. Find the value of a.

• a=5.5

• a=4.5

• a=9.5

• 7.5

Which box and whisker plot is a summary of a data set with range 40, median 20 and interquartile range 20.

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Two distributions, A and B, are summarized in the two box-and-whisker plots. Which of the following statements about the distributions is not true?

• The interquartile range (IQR) of distribution A is equal to the IQR of distribution B.

• The range of data in distribution A is less than the range of data in distribution B.

• The maximum value in distribution A is equal to the third quartile in distribution B.

• The median in distribution A is equal to the median in distribution B.

This is the set of data:

11, 12, 19, 20, 20, 20, 21, 21, 22, 22, 25, 27, 30.

Determine if there are outliers in the above ordered list.

If there are, write them in ascending order, separating them by commas with no blanks.

If there are no outliers, write none.

The diagram below shows a box-and-whisker plot of a set of data.

What is the range of the data?

11. A researcher measured the length of 200 insects. The cumulative frequency graph below illustrates his measurements.

How many of these insects are longer than 8cm?

Consider the following data set:

21, 23, 25, 26, 27, 27, 28, 29

Which of the following statements about the data set above is NOT true?

• The standard deviation is 2.49 to 3 significant figures.

• The range is 3.5.

• The interquartile range is 3.5.

• The median is 26.5.