A teacher tossed four unbiased coins.

Four of his students wrote the following statements about the probability of results.

Shiela The probability of having neither 4 heads nor 4 tails is 1/2

Max The probability of having 2 heads and 2 tails is 1/2.

Nathan The probability of having all heads is the same as the probability of having all tails.

Violet The probability of having more heads than tails is 1/4.