Question: This problem makes use of the attached SPSS data set lowbwt. The data set lowbwt contains information for a sample of 100 low birth weight infants born in two hospitals. Measurements of systolic blood pressure are saved under the variable name sbp and indicators of gender -- with 1 representing a male and 0 a female under the name sex.

(a) Construct a histogram of systolic blood pressure measurements for this sample. Based on the graph, do you believe that blood pressure is approximately normally distributed?

(b) Test the null hypothesis that among low birth weight infants, the mean systolic blood pressure for boys is equal to the mean for girls. Use a two-sided test at the 0.05 level of significance. What do you conclude?