Question: A study in Pittsburgh looked at various cardiovascular risk factors in children, as measured at birth and during their first five years of life in particular, heart rates was assessed at birth, 5 months, 15 month, 24 months and annually after until 5 years of age. Heart rate was related to age, sex, and race and socioeconomic status. The data in table were presented relating heart rate to race among newborns.

Race Means* sd n

White 125 11 218

Black 133 12 156

*beats per mean

Test for a significance difference in mean heart rate between white and black newborns.

Do the four steps method given in all the examples in the text.