The SoftBus Company sells PC equipment and customized software to small companies to help them manage their day-to-day business activities. Although SoftBus spends time with all customers to understand their needs, the customers are eventually on their own to use the equipment and software intelligently. To understand its customers better, SoftBus recently sent questionnaires to a large number of prospective customers. Key personnel— those who would be using the software—were asked to fill out the questionnaire. SoftBus received 82 usable responses, as shown in the file. You can assume that these employees represent a random sample of all of SoftBus's prospective customers.

Construct a histogram of the PCKnowledge variable. [Because there are only five possible responses (1-5), this histogram should have only five bars.] Repeat this separately for those who own a PC and those who do not. Then find a 95% confidence interval for the mean value of PCKnowledge for all of SoftBus's prospective customers; of all its prospective customers who own PCs; of all its prospective customers who do not own PCs. The PCKnowledge variable obviously can't be exactly normally distributed because it has only five possible values. Do you think this invalidates the confidence intervals? Explain your choice.