25,8,10,35,5,45,30,20
what is the lower quartile of th data set above
a.5
b.8
c.9
d.10

which. way describes box -and-whisker plots ?
a. they are divided into sections using quartiles and extremes.
b. theu are created by first writing a data set in order from least to greatest.
c. they show how data are spread out.
d. all of the above
in constructing a box-and-whisker plot for the data set below, at which values would you draw the left and right sides of he box?
6,7,1,3,9,3,2,5,8,4,8

a. left at 3; right at 8
b. left at 2; right at 8
c. left at 2; right at 7
d. left at 3; right at 7

Part 1:
The lower quartile of a data is the value which divides the lower half of a data into two equal parts.

Given the data set: 25,8,10,35,5,45,30,20
Arranging the data set, we have:
5, 8, 10, 20, 25, 30, 35, 45

The lower half of the data set is: 5, 8, 10, 20 and half of the lower half of the data is given by (8 + 10) / 2 = 18 / 2 = 9.

Therefore, the lower quartile of the data set is 9.   (option c)

Part 2:
The box -and-whisker plots are divided into sections using quartiles and extremes.
In a box and whisker, the end point of the left whisker represents the minimum value while the right whisker represents the maximum number.
The left edge of the box represent the lower quartile while the right edge of the box represent the upper quartile.

A line inside the box represent the median of the data set.

Part 3:
In constructing a box-and-whisker plot for the data set below, the left and right sides of the box is drawn at the lower and the upper quartile of the data set.

Arranging the dat set, we have:
1, 2, 3, 3, 4, 5, 6, 7, 8, 8, 9
The lower quartile of the data set is 3 while the upper quartile of the data is 8.

Therefore, the left side of the box is at 3 while the right side of the box is at 8.