18. In a study of author productivity (“Lotka’s Test,” Collection Mgmt., 1982: 111–118), a large number of authors were classified according to the number of articles they had published during a certain period. The results were presented in the accompanying frequency distribution:

Number of papers 123 45 678 Frequency 784 204 127 50 33 28 19 19 Number of papers 9 10 11 12 13 14 15 16 17 Frequency 67674 4533

a. Construct a histogram corresponding to this frequency distribution. What is the most interesting feature of the shape of the distribution?

b. What proportion of these authors published at least five papers? At least ten papers? More than ten papers?

c. Suppose the five 15s, three 16s, and three 17s had been lumped into a single category displayed as “15.” Would you be able to draw a histogram? Explain.