The table on the next page gives a frequency distribution describing the number of errors found in 30 l,000-line samples of computer code. Suppose that we wish to determine whether the number of errors can be described by a Poisson distribution with mean µ = 4.5. Using the Poisson probability tables, fill in the table. Then perform an appropriate chi-square goodness of fit test at the .05 level of significance. What do you conclude about whether the number of errors can be described by a Poisson distribution with µ = 4.5? Explain.

Observed Expected Frequency Number of Errors 0-1 2-3 4-5 6-7 8 or more Probability Assuming Errors Are Poisson Distributed with 4.5 6 7 4