Answer
$P(not$ $30-39)=\frac{2620}{6427}\approx0.408$
If we randomly select 1000 mothers involved in a multiple birth we would expect about 408 to be a mother who was not 30 to 34 years old.
Work Step by Step
According to 29.a:
$P(30-39)=\frac{3807}{6427}$
The event "mother who was not 30 to 34 years old involved in a multiple birth" is the complement of "mother 30 to 34 years old involved in a multiple birth". So:
$P(not$ $30-39)=1-\frac{3807}{6427}=\frac{6427}{6427}-\frac{3807}{6427}=\frac{2620}{6427}\approx0.408$
