Question

The Taylors have recorded their weekly grocery expenses for the past 12 weeks and determined that the mean weekly expense was ​$.82.55. Later Mrs. Taylor discovered that one​ week's expense of​ $74 was incorrectly recorded as​ $47. What is the correct​ mean?

Answer 1

$84.80

Explanation:

find the difference between accurate price and written price: 74 - 47 = 27

find written total (before Mrs. Taylor found mistake) by undoing the mean calculation: 82.55 x 12 = $990.60

the total expenses is $27 more than what they thought: 990.60 + 27 = 1017.60

divide accurate total by 12 to find mean: 1017.60 / 12 = $84.80

hope this helps :)