A professor had students keep track of their social interactions for a week. The number of social interactions over the week is shown in the following grouped frequency distribution.Identify the lower limit of the first class.

Number of Social Interactions:

25-29

30-34

35-39

40-44

45-49

50-54

55-59

60-64

65-69

70-74

Frequency:

15

17

17

18

20

8

5

4

0

2