Data was collected on head circumference (in cm) for 100 low birth weight infants, which was defined as those weighing less than 1500 grams. For each infant, the gestational age (in weeks) and birth weight (in grams) were measured. It is known that head circumferences of newborn infants increase with gestational age. Moreover, for a specified age x, the distribution of those circumferences is normal. A simple regression analysis was performed, and the results are summarized in Table 1 below

It was later suggested that there might be a relationship between head circumference and birth weight. A multiple linear regression analysis was performed to analyze the contribution of birth weight in predicting head circumference given the gestational age (Table 2).

"Table 1: Simple Linear Regression Variable Coefficient SE t-statistic 95 % CI Intercept 3.9 1829 2.14 10.29 753 Gestational 0 78 0.063 12.37 10.655. Age 0.905)