During a behavioral experiment in a psychology class, each student is

We need to know 2 things to answer this question.

First, each student's lucky number will ALWAYS be an ODD INTEGER.
We know this because...
lucky number = 7^(student's favorite day of the week - 1,2,3.. or 7) x 3 + (doubled ages of students in years)
In other words, lucky number = (ODD INTEGER x ODD INTEGER) + EVEN INTEGER
= ODD INTEGER + EVEN INTEGER
= ODD INTEGER

Second, when we have an even number of values (28 values), the MEDIAN equals the average (arithmetic mean) of the two middle-most integers (when all of the integers are arranged in ascending order).

Since all 28 values are guaranteed to be ODD (see point #1 above), then we know that the two middle-most integers will be ODD.
So, the median of the 28 values = (some ODD integer + some ODD integer)/2
= (an even integer)/2
= an integer.
In other words, the median of the 28 values is GUARANTEED to be an integer.

So, P(the median of the lucky numbers will be a non-integer) = 0%

Answer: A

RELATED VIDEO FROM OUR COURSE