Research has shown that for mammals giving birth to a son versus a daughter places a greater strain on mothers. Does this affect teh health of their next child? A study compared the birthweights of humans born after a male versus after a female. Summarystatistics for the sample of size 76 are given in the following table, the data appear to be normally distributed.
Use a t test with a=0.05 and a directinal alternative, to investigate the research hypothesis that birthweight is lower when the elder sibling is male.
DF: 69.5
male: n=33 mean=3.32 sd=0.62
female: n=43mean=3.63sd=0.63