A retrospective study of 159 pairs of twins was performed. Thetwin pairs each had one male child and one female child. Theirbirth weights were studied to determine if the male twin wasconsistently heavier.
The difference in weights was calculated by subtracting thefemale weight (in ounces) from the male weight (in ounces):
d=xm-xf
After looking at 159 pairs of twins, the study finds the 99%confidence interval for the mean difference of weights (in ounces)is:
2.4 < ?d < 6
Can we be reasonably sure that the male twins are heavier thanthe females?
Why or why not?
