Answer
False
Work Step by Step
We can determine whether or not each proportion is true by writing both sides of the proportion with the same denominator. If both sides also have the same numerator when written as like fractions, we know that the proportion is true.
Left side: $\frac{150}{200}=\frac{150\times3}{200\times3}=\frac{450}{600}$
Right side: $\frac{200}{300}=\frac{200\times2}{300\times2}=\frac{400}{600}$
Therefore, this is not a true proportion, because both sides have different numerators when written with the same denominator.