Complete
Solution:
Helix will bowl a total of six
games. To reach an average of at least 114,
his total score must be at least
6 ×
114, or 684. The sum of his scores after five
games is 560.
Subtracting 560
from 684 leaves 124. Therefore, any score 124
or higher will result in a win for Helix.
Now, consider that Helix
has scored higher than 124 in only one of the previous
five games. Based on these performances, you
might estimate that his chances of winning are 1/5, or
20%.
Alternative Approach:
Another way to figure the average is to subtract
114 from each score and add the differences.
In order, his scores are +20, –15, –5, +3, –13
from 114.
The total is:
+ 20 + (–15)
+ (–5) + 3 + (–13) = –10
He must score at
least 10 above the desired average of 114 to compensate,
or 124, again having 1/5 chance, or 20%. |