sat suite question viewer
Data set A consists of positive integers less than . The list shown gives of the integers from data set A.
, , , , , , , ,
The mean of these integers is . If the mean of data set A is an integer that is greater than , what is the value of the largest integer from data set A?
Explanation
The correct answer is . The mean of a data set is calculated by dividing the sum of the data values by the number of values. It’s given that data set A consists of values, of which are shown. Let represent the data value in data set A, which isn’t shown. The mean of data set A can be found using the expression , or . It’s given that the mean of the values shown is and that the mean of all numbers is greater than . Consequently, the data value, , is larger than . It’s also given that the data values in data set A are positive integers less than . Thus, . Finally, it’s given that the mean of data set A is an integer. This means that the sum of the data values, , is divisible by . Thus, must have a ones digit of . It follows that must have a ones digit of . Since and has a ones digit of , the only possible value of is . Since is larger than any of the integers shown, the largest integer from data set A is .