Question

96. Construct a frequency distribution table from
the following cumulative frequency table :
Class interval Cumulative frequency
0-9
15
10-19
23
20-29
38
30-39
56
40-49
68
50-59
90​

Answer 1

The given frequency distribution is not continuous. So, we first make it continuous and prepare the cumulative frequency distribution as under.

(do as given in 1st photo)

Now, we plot points (9.5,5),(19.5),(29.5,40),(39.5,63),(49.5,80),(59.5,91)and(69.5,100). and join them by a free hand smooth curve to obtain the required ogive as shown in Fig. 7.5. 

The cumulative frequency polygon is obtained by joining these points by line segments as shown in Fig. 7.6