The following frequency histogram represents the iq scores of a random sample of​ seventh-grade students. iqs are measured to the nearest whole number. the frequency of each class is labeled above each rectangle. use the histogram to answers parts​ (a) through​ (g). iqs of 7th grade students 60 70 80 90 100 110 120 130 140 150 160 0 20 40 60 80 iq scores frequency 1 3 13 46 48 42 32 9 4 2 a histogram titled “iqs of seventh grade students” with a horizontal axis labeled “iq scores” from less than 60 to 160 plus in increments of 10 and a vertical axis labeled “frequency” from 0 to 80 in increments of 10 contains vertical bars of class width 10 with heights as follows, where the horizontal axis ranges are listed first and the heights are listed second: 60 to 70, 1; 70 to 80, 3; 80 to 90, 13; 90 to 100, 46; 100 to 110, 48; 110 to 120, 42; 120 to 130, 32; 130 to 140, 9; 140 to 150, 4; 150 to 160, 2. each bar is labeled with its height. ​(a) how many students were​ sampled? 200 students ​(b) determine the class width.