Step-by-step explanation:
There is 7 blocks that measure is 12.0-12.2
11 blocks that measure 12.2 to 12.4
18 blocks that measure 12.4 to 12.6
10 blocks that measure 12.6-12.8
4 blocks that measure 12.8 to 13.0
We can't find a mean by with Intervals so let find the midpoint of each interval,
12.1, 12.3, 12.5, 12.7, 12.9.
- 12.1 occurs 7 times so that equal 12.1 x 7=84.7
- 12.3 occurs 11 times so that equal 12.3 x 11=135.3
- 12.5 occurs 18 times so that equal 12.5x18=225
- 12.7 occurs 10 times so that equal 12.7x10=127
- 12.9 occurs 4 times 12.9×4=51.6
Add up the products and divide them by 50
[tex]\frac{623.6}{50} = 12.472[/tex]
Standard Deviation is
0.23( it is alot of steps so I use a calculator to save time).
The interqualtie range is 0.4
