A wholesaler has recently developed a computerized sales invoicing system. Prior to implementing this system, a manual system was used. The distribution of the number of errors per invoice for the manual system is as follows: After implementation of the computerized system, a random sample of 500 invoices gives the following error distribution: (a) Show that it is appropriate to carry out a chi-square test using these data. (b) Use the Excel output shown above to determine whether the error percentages for the computerized system differ from those for the manual system at the 05 level of significance. What do you conclude