13. Johnson et al. (A-16) performed a retrospective review of 50 fetuses that underwent open fetal myelomeningocele closure. The data below show the gestational age in weeks of the 50 fetuses undergoing the procedure.

25 25 26 27 29 29 29 30 30 31 32 32 52 33 33 33 83 34 34 84 85 35 35 3.5 35 35 35 35 35 36 36 36 36 36 36 36 96 36 36 36 36 36 36 36 36 36 36 36 37 37 SOURCE: Mark P. Johnson, Leslie N. Sutton, Natalie Rintoul, Timothy M. Crombleholme, Alan W. Flake, Lori J. Howell, Holly L. Hedrick," R. Douglas Wilson, and N. Scout Adrick, Tetal Myelomeningocele Repair Short-term Clinical Outcomes," American Journal of Obstetrics and Gynecology, 189 (2003), 482-487.

(a) Construct a stem-and-leaf plot for these gestational ages.

(b) Based on the stem-and-leaf plot, what one word would you use to describe the nature of the data?

(c) Why do you think the stem-and-leaf plot looks the way it does?

(d) Compute the mean, median, variance, and standard deviation.