Suppose the experiment is to flip a coin four times and observe the side facing up. Let H represent head and T represent rail. Represent the outcomes as a string of four letters; for example, TTHT represents flipping tail, rail, head, rail. How big is the sample space? What is the sample space, S, of this experiment? (Enter the outcomes as a comma separated list; the curly braces are provided.) s={} Ler E be the event of flipping only cails. Determite the outcomes in E. (Enter the outcomes as a comma separated list the curly braces are provided.) Let F be the event of flipping ar least three heads. Determine the ourcornes in F. (Enter the outcomes as a comma separated liss, the curly braces are provided.)