8. The Sales Manager at Hybrid Industries a high-tech farming agency claims that there has been a drop in the sales from the target of $2,800 per week. Data was collected for the last 48 weeks and the sample mean was computed as $ 2,435 with a standard deviation of $351. Verify at 5% level of significance if the manager's claim can be accepted based on the sample observations.

9. Guests travelling on two different airlines (West Fly Airlines and Air Cosmos) were surveyed for their satisfaction levels of the services offered. 123 of 180 guests travelling by West Fly and 157 of the 200 guests travelling by Air Cosmos rates the respective airlines high on service quality. Do the data provide enough evidence to infer that there is no significant difference between the service qualities of the two airline companies? (Use 5% level of significance)