Is this coin fair? The French naturalist Count Buffon (1707–1788) tossed a coin 4040 times. He got 2048 heads. That’s a bit more than one-half.

Is this evidence that Count Buffon’s coin was not balanced? To find out, Luisa decides to perform a significance test. Unfortunately, she made a few errors along the way. Your job is to spot the mistakes and correct them.

H0 : m > 0.5 Ha : x– = 0.5

• 10%: 4040(0.5) = 2020 and 4040(1 – 0.5) = 2020 are both at least 10.

• Large Counts: There are at least 40,400 coins in the world.

t =

0.5 − 0.507

Å

0.5(0.5)

4040

= −0.89; P-value = 1 − 0.1867 = 0.8133 Reject H0 because the P-value is so large and conclude that the coin is fair.