The following datarepresents the number of automobiles arriving at a toll booth during 20 intervals, each of ten-minute duration. Compute the mean, median, mode, first quartile, and third quartile for data… (please see attachment for remainder of questions).

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Ch 3

Ex. 11

The following data represents the number of automobiles arriving at a toll booth during 20 intervals, each of ten-minute duration. Compute the mean, median, mode, first quartile, and third quartile for data.

26 26 58 24 22 22 15 33 19 27

21 18 16 20 34 24 27 30 31 33

Solution. Mean=[26+26+58+…+30+31+33]/20=26.3

Median=25

How to get it? You can re-order the data in increasing order:

15,16, 18, 19, 20, 21, 22, 22, 24, 24 , 26,26, 27, 27, 30, 31, 33,33, 34, 58.

Then you can find two numbers in the middle(since the total is 20 which is even, if the total is odd, then there is only one number in the middle) which are 24 and 26. So, the average is 25. So the Median is 25.

Mode=26

First quartile=(20+21)/2=20.5

The first quartile is the median of the lower half of the data, that is, the median of

15,16, 18, 19, 20, 21, 22, 22, 24, 24, is 20.5;

Third quartile=(30+31)/2=30.5

The third quartile is the median of the upper half of the data, …

The following data represents the number of automobiles arriving at a toll booth during 20 intervals, each of ten-minute duration. The solution computes the mean, median, mode, first quartile, and third quartile for data.