The length of pregnancy that separates premature babies from those who are not premature is approximately 269
Explanation:The length of pregnancies is given as 268 days, and the standard deviation is 15 days.
We want to find the length that separates premature babies from those who are not premature, we use the Z transform
[tex]\begin{gathered} Z=\frac{x-\mu}{\sigma} \\ \\ \mu=268 \\ \sigma=15 \\ \\ 0.07=\frac{x-268}{15} \\ \\ x-268=0.07\times15=1.05 \\ \\ x\text{ }=268+1.05=269.05 \end{gathered}[/tex]The length of pregnancy that separates premature babies from those who are not premature is approximately 269