Question: A wholesaler has recently developed a computerized sales invoicing system. Prior to implementing the new system, the manager of the store believes that the following are in fact the percentages of the number of the errors per invoice:

Errors per invoice

After implementing, the new system, a random sample of 500 invoices gives the following

error distribution:

Do you think that the original claim of the manager (prior to implementing the new system) is correct at a significance level of 5%? Please state your null/alternative hypothesis (both verbally and symbolically), test statistic and your rejection region clearly. And show how they are calculated.