Box and Whisker Plot Questions, and Comparing Data.

the mean

(or average) Is the sum of all values divided by the number of cases.

5

1. What is the interquartile range for the information shown in the above box and whisker plot? A. 7.5 B. 5 C. 3 D. 2

D.

10. Which box plot represents a situation where 75% of the data is 200 or less?

What is the mode for the following sample of n=8 scores? Scores: 0, 1, 1, 2, 2, 2, 2, 3

2

range = 14. IQR = 10

2. For the information shown in the box and whisker plot, what is the range and what is the interquartile range? A. range = 15, IQR = 10 B. range = 14, IQR = 10 C. range = 14, IQR = 9 D. range = 5.5, IQR = 4.5

median = 6.5, range = 14, IQR = 10

3. For the information shown in the box plot, what are the median, range and interquartile range? A. median = 6.5, range = 14, IQR = 12 B. median = 6.5, range = 15, IQR = 10 C. median = 7, range = 14, IQR = 10 D. median = 6.5, range = 14, IQR = 10

What is the variance for the set of scores in the following table? X 1 2 4 5

3.33

The box plot is correct

4. The high temperatures for Concord, CA, for October 1-15, 2005, are given. Look at the box plot of these data below. What, if anything, is wrong with this box plot? A. The value of the lower quartile is incorrect. B. The median is incorrect C. The value of the upper quartile is incorrect D. The box plot is correct

What is the mean for the following scores? Scores: 1, 4, 5, 10

5

35

5. The box plot shows the masses, in grams, of several specimens of rock collected by a geologist. What is the range of the masses? A. 35 B. 33 C. 36 D. 12

B.

6. The data set 5, 6, 7, 8, 9, 9, 9, 10, 12, 14, 17, 17, 18, 19, 19 represents the number of hours spent on the internet in a week by students in a math class. Which box plot represents this data?

What is the median for the following set of scores? Scores: 1, 3, 4, 6, 7, 8, 12, 23

6.5

A.

7. The number of laps around a track for five runners are 14, 8, 7, 4, 12. Display the data using a box plot.

D. 34

8. The performance review for several employees at a company are shown in the box plot. What is the range of the performance review scores? A. 31 B. 36 C. 20 D. 34

D. median or range

9. The box and whisker plot shows the number of hours students in Holly's class spent volunteering last summer. Which of the following would be the most accurate measure of central tendency for the data? A. mean or mode B. mean or median C. mode or range D. median or range

Box Plot

A graph that displays the highest and lowest quarters of data as whiskers, the middle two quarters of the data as a box, and the median

Bar Graph

A graph that uses horizontal or vertical bars to display data

steps for calculating the variance and standard deviation-

Find the mean For each case, subtract the case's score to determine the deviation from the mean Square each deviation score Sum the squared deviation score Divide the sum of the squared deviation scores by (n-1) To find the standard deviation, take the square root of the variance

range

The difference between the maximum and minimum value.

Interquartile Range

The difference between the upper and lower quartiles.

C. Q3 - Q1

The interquartile range is calculated by: A. Finding the middle number or median B. The maximum minus the minimum C. The upper quartile (Q3) minus the lower quartile (Q1) D. Finding the mean of the data

B. 50%

The interquartile range of a box and whisker plot represents what percent of the data? A. 25% B. 50% C. 75% D. 100%

Lower Quartile or Q1

The median of the lower half of the data.

Upper Quartile or Q3

The median of the upper half of the data.

median

The middle number in a set of ordered data.

Median

The middle number, or the mean (average) of the two middle numbers, in an ordered set of data

Mode

The number that occurs most often in a set of data

Interquartile Range

The range of the data from the lower quartile to the upper quartile. Q3-Q1

Mean

The sum of the items in a set of data divided by the number of items in the set; also called average

A. 25%

The upper quartile of a box and whisker plot represents what percent of the data? A. 25% B. 50% C. 75% D. 100%

25% of the data

The value represented by each whisker

mode

The value that occurs most frequently in a given data set.

Dot Plot

a graphical device that summarizes data by the number of dots above each data value on the horizontal axis

mean

average

range

highest value minus lowest value r= x highest- x lowest EXAMPLE X 2 4 5 9 Range = 9 - 2 Range = 7

outlier (extreme value)

is a value that is markedly higher or lower than other values.

50% of the data

represented by the box (excluding the whiskers) in a box & whisker plot

the median

the value with the same number of values greater than and less than its value.