Question

4. Four numbers with mean 7.5, mode 6 and median 7 for grade 7​

Answer 1

Number set in order: 6, 6, 8, 10

Explanation:

Let the four numbers be represented by a, b, c and d;

Mean = ¹/₄(a + b + c + d) = 7.5

a + b + c + d = 30

Mode is 6, which, by extension, means there is a mode, thus 6 must be the most common number;

This has to mean at least 2 of the numbers are 6;

With the median being 7, we know:

¹/₂(b + c) = 7

b + c = 14

b has to be 6, meaning c is 8;

a must also be 6, making d equal to 10.