Question

Emilio flipped a pair of fair coins 60 times. On 24 occasions, heads appeared on both coins. How is this outcome different from the expected outcome?

It occurred 6 fewer times than expected.
It occurred 4 more times than expected.
It occurred 9 more times than expected.
It occurred the expected number of times.

Answer 1

P(heads on both coins) = (1/2)(1/2) = 1/4

E(heads on both coins) = (1/4)(60) = 15

It occurred 9 more times than expected.