uppe

First question:

We are given;

Minimum data point=21
Maximum data point=110
Number of classes=8
Lowest lower limit=20

First, we will calculate the range. The formula and calculations are as follows;

Range=Maximum data point-Minimum data point
          =110-21
          =89

Now, we will find the class width of each class that is present. The formula and calculations are shown as follows;

$$\begin{gathered} Class width=\frac{Range}{Number of classes} \\ =\frac{89}{8} \\ =11.125 \\ \approx 12 \end{gathered}$$

Class width is basically the difference between the lower and upper class limit of an interval/class.
Now, we know that lowest lower limit is 20. But the minimum data point is 21. Hence we will add 12, i.e, class width to 21 to obtain the lowest upper limit.

Lowest upper limit=21+12
                             =33

Therefore, the lowest upper limit=33