The width of each of nine classes in a frequency distribution is 2.5 and the lower class boundary of the lowest class 10.6. Then the upper class boundary of the highest class is 35.6      (b)  33.1          (c)  30.6            (d)  28.1

Explanation

Width of each class = `2.5`
No. of classes = `9`
Lower class boundary of the lowest class = `10.6`
∴ Upper class limit of highest class`= 10.6 +9 xx 2.5`
`= 10.6 + 22.5 = 33.1`