Many automobile accidents are caused by tired drivers. A typical test for alertness involves measuring the speed and degree to which a person’s eyes respond to certain stimuli.9 A random sample of 25...

Many automobile accidents are caused by tired drivers. A typical test for alertness involves measuring the speed and degree to which a person’s eyes respond to certain stimuli.9 A random sample of 25 drivers was obtained, and the oscillations in pupil size (x, in millimeters per second) was measured using a pupillograph. Each person’s tiredness ( y) was also recorded using the pupil unrest index (PUI). The summary statistics are given below.

Ultrasound measurements are often used to predict the birth weight of a newborn. However, there is some evidence to suggest that pre-pregnancy body mass index (BMI) is related to birth weight.11 A random sample of Caucasian pregnant women experiencing no complications was obtained. The BMI pre-pregnancy (x, in kg/m2 ) of each was measured, and the newborn weight (y, in grams) was also recorded. NEWBORN

a. Construct a scatter plot for these data.

b. Find the estimated regression line.

 c. Estimate the expected weight of a newborn if the mother’s pre-pregnancy BMI is 25 kg/m2 .

d. If ultrasound is not available, do you believe that BMI is a good predictor of birth weight? Why or why not?