Really need help with part c

Homework Problem Kelly surveyed 13 other seventh grade students to find out the number of days it had been since the last time they were given math homework. The results are shown in the line plot below. Days since Being Assigned Math Homework 6 7 10 Number of Days Part A What is the median number of days represented on Kelly's line plot? 3.5 Part B What is the interquartile range of the number of days represented on Kelly's line plot? Be sure to show your work and explain your reasoning. 3 The interquartile range is the difference between the third quartile and first quartile. 5 - 2 = 3 Part C Two days later, Kelly surveyed the same 13 classmates and found that none of them had been given math homework since she last surveyed them. By how much does the mean of Kelly's second data set change in comparison with the mean of the data set in her original survey? Explain how to determine the change in the means without calculating the mean of either data set