Question

When manufactured, pennies need a beveled edge (slightly angled) to help pop them out of the press. For this reason, it has been conjectured that spinning a penny on its edge is more likely to land with the tail side up than with the head side up. Suppose you investigate by spinning a penny 15 times (put it on its edge and flick it to spin on its own) and that you find that the penny lands with the tail side up 13 times. You determine that if a spun penny is equally likely to land tails or heads, then the probability of 13 or more tails in 15 coin spins is 0.004. What does this analysis tell you about whether this penny is more likely to land tails than heads if spun a large number of times?

Getting 13 tails in 15 spins likely happened just by chance and therefore this penny has a 50-50 chance to land tails when spun a large number of times.

There is strong evidence that this coin is more likely to land tails than heads if spun a large number of times.

These results prove that this penny is more likely to land tails than heads when spun a large number of times.

Nothing, spinning the penny only 15 times does not produce conclusive evidence either way.

Answer 1

Correct option:

There is strong evidence that this coin is more likely to land tails than heads if spun a large number of times

Explanation:

Probability of 13 or more tails in 15 coin spins is 0.004. This is an unusual event So, if the experiment is repeated a large number of times, there is strong evidence of getting more tails than heads.