13. The lengths of human pregnancies are normally distributed with a mean of 268 days, and a standard deviation of 15 days. What percent of all pregnancies are between 238 and 298 days? (10) 14. The frequency distribution table below contains the total number of students enrolled in all the Statistic classes each year at a small college. Year Total number of Students 2010 220 2011 324 2012 219 2013 250 2014 380 2015 320 2016 290 a. What percent of the students were enrolled in these classes in 2012? ( 3 points b. What percent of the students were enrolled in these classes before 2012? ( 3 points ) c. What kind of data is the total number of students? (3 points ) 15. The frequency distribution table below shows the number of minutes students took to finish a Statistics test. (10 points) Number of Frequency minutes 40 -49 9 50-59 14 60 -69 29 70 -79 17 80 - 89 7 90 - 99 5 a. Construct a relative frequency distribution of the data. (7) b. Contract a cumulative frequency distribution of the data. (7) c. Construct a histogram of the data. (7) 16. The number of Students in Statistics classes, were: 19, 23, 57, 32, 29, 53, 32, 23, 37, 50, 23, 52, 37, 37, and 38. a. Construct a stem-and-leaf display of the data. (5) b. Find the median. (5) c. Find the range. (5) d. Find the mode. (5) e . Find thes number F. construct a box plot