A Person S Intelligence Quotient ( I ) Is Found $I = \frac { 20 \mathrm { M } } { C }$

Multiple Choice

A person s intelligence quotient ( I ) is found by dividing mental age ( M ) , as indicated by standard tests, by chronological age ( C ) and then multiplying this ratio by 20. The formula $I = \frac { 20 \mathrm { M } } { C }$ can be used. If the I range of a group of 12-year-olds is given by $76 \leq I \leq 189$ , find the range of the mental age of this group.

A) $3.8 \leq M \leq 9.45$
B) $912 \leq M \leq 2268$
C) $76 \leq M \leq 189$
D) $45.6 \leq M \leq 113.4$
E) $91.2 \leq M \leq 226.8$