LCD is 20
3/5 -> 12/20
1/20 -> 1/20
54/35 is the answer to this question
I think the group 2 survey is likely to be biased towards people who are not too keen on zoos since all the values are small.
From group 1 and 3 the mean number of visits are
(4 + 10 + 6 + 3 + 8 + 7 + 9 + 3 + 4 + 7) / 10
= 61/10
mean = 6