Ctween 3 and 4. 8. A coin is tossed 100 times. (a) The difference "number of heads - number of tails" is like the sum of 100 draws from one of the following boxes. Which one, and why? (i) heads tails (ii) -1 (iii) -1 0 (iv) 0 (v) -1 0 1 (b) Find the expected value and standard error for the difference