Birth Weights. The WONDER database, maintained by the Centers for Disease Control and Prevention, provides a single point of access to a wide variety of reports and numeric public health data.

From that database, we obtained the following data for one year’s birth weights of male babies who weighed under 5000 grams (about 11 pounds).

Weight (g) Frequency 0–under 500 2,025 500–under 1000 8,400 1000–under 1500 10,215 1500–under 2000 19,919 2000–under 2500 67,068 2500–under 3000 274,913 3000–under 3500 709,110 3500–under 4000 609,719 4000–under 4500 191,826 4500–under 5000 31,942

a. Obtain a relative-frequency histogram of these weight data.

b. Based on your histogram, do you think that, for the year in question, the birth weights of male babies who weighed under 5000 grams are approximately normally distributed? Explain your answer.