2.44 [EX02-044] The hemoglobin A1c test, a blood test given to diabetics patients during their periodic checkups, indicates the level of control of blood sugar during the past 2 to 3 months. The following data values were obtained for 40 different diabetics patients at a university clinic:

6.5 5.0 5.6 7.6 4.8 8.0 7.5 7.9 8.0 9.2 6.4 6.0 5.6 6.0 5.7 9.2 8.1 8.0 6.5 6.6 5.0 8.0 6.5 6.1 6.4 6.6 7.2 5.9 4.0 5.7 7.9 6.0 5.6 6.0 6.2 7.7 6.7 7.7 8.2 9.0

a. Classify these A1c values into a grouped frequency distribution using the classes 3.7–4.7, 4.7–5.7, and so on.

b. What are the class midpoints for these classes?

c. Construct a frequency histogram of these data.