As any power of 7 is odd, the product of 7^any integer and 3 will always be odd.

Sum of this odd number & double the age of a student will always be odd.

Therefore, all lucky numbers in the class will be odd.

The results of the experiment will yield a set of 28 odd integers

Arrange the numbers in ascending order.

Median of the set will be average of the 14th & 15th elements in the set.

Both these integers are odd; hence, their sum will always be even and their average will always be an integer.

Therefore, the probability that the median lucky number in the class will be a non-integer is 0%.

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