Joe likes to go to an old arcade and play 12 games of Skeeball every day. On average, he wins a prize on 55% of the games he plays. Today, however, he won only 4 of the 12 games he played.This made Joe think that there must be something wrong with how he is throwing the ball today. However, a friend tells him, "You might be throwing the same way you usually do. People will sometimes have a group of bad games just because of random variation, not because of psychology, or because they are doing anything differently, or any other reason. For someone with your statistics, such random bad days wouldn't even be very rare."Let's see what Joe's friend means. Suppose that Joe's skill level really hasn't changed, so he still has a 55% chance of winning each game he plays, like before. If he plays 12 games a day, on what percentage of days will he win 4 games or fewer? Assume that each game is independent of the others.
Joe likes to go to an old arcade and play 12 games of Skeeball every day. On average, he wins a prize on 55% of the games he plays. Today, however, he won only 4 of the 12 games he played.
This made Joe think that there must be something wrong with how he is throwing the ball today. However, a friend tells him, "You might be throwing the same way you usually do. People will sometimes have a group of bad games just because of random variation, not because of psychology, or because they are doing anything differently, or any other reason. For someone with your statistics, such random bad days wouldn't even be very rare."
Let's see what Joe's friend means. Suppose that Joe's skill level really hasn't changed, so he still has a 55% chance of winning each game he plays, like before. If he plays 12 games a day, on what percentage of days will he win 4 games or fewer? Assume that each game is independent of the others.
Trending now
This is a popular solution!
Step by step
Solved in 5 steps with 2 images
