Tim carried out an experiment where he tossed 20 coins together and observed the number of heads showing. He repeated this experiment 10 times and got the following results

11,9,10,8,13,9,6,7,10,11

a) Use Tim's data to get the probability of obtaining a head.

the ans to this was .47 but I don't know how that was derived

b) He tossed the 20 coins for the 11th time, How many heads should he expect to get?

I would guess 9 but not sure what the mathematical calc would be

c) He tossed the coins 1000tmes. How many heads should he expect to see.

since this a much longer data base I would think this would smooth out to

50% or 500 heads