Which of the following ratios is not equivalent to the following statement: The ratio of right-handed students to left-handed students is 18:4

A9:2

B 36:8

C 8:2

D 54:12

In (A), we have 9 : 2.

Multiply by 2, we get 18 : 4

In (B), we have 36 : 8.

Divide by 2, we get, 18 : 4.

In (D), we have 54 : 12.

Divide by 3, we get, 18 : 4.

Hence, (C) is not equivalent to the given statement.