In a survey, 26 voters were asked their ages. Their results are shown below. Construct a histogram to represent the data (with 5 classes beginning with a lower class of 20 and a class width of 10). What is the approximate age at the center?
43 56 28 63 67 66 52 48 37 51 40 60 62
66 45 21 35 49 32 53 61 53 69 31 48 59