1. It is claimed that the average age of working students in a certain university is 35. A researcher selected a random sample of 25 working students. The computation of their ages resulted to an average of 32 years with standard deviation of 10 years. 2. A manufacturer of tires claim that their tire has a mean life of at least 50,000kms. A random sample of 28 of these tires is tested and the sample mean is 33,000kms. Assume that the population standard deviation is 3,000kms and the lives of the tires are approximately normally distributed. 3. On average, a drinking vending machine is adjusted so it dispenses 240ml of fruit juice. However, the machine tends to go out of adjustment and periodic checks are made to determine the average amount of fruit juice being dispensed. A sample of 28 with a standard deviation of 15ml in plastic cup drinks is taken to test the adjustment of the machine. 4. Uber company claims that the mean time to rent a car on their app is 60 seconds with a standard deviation of 30 seconds. A random sample of 36 customers attempted to rent a car on the app. The mean time of renting was 75 seconds. Is this enough evidence to contradict the company's claim? 5. The waiting time to be seated at the restaurant has population standard deviation of 10 minutes. An expensive restaurant claims that the average waiting time for dinner is approximately 1 hour, but we suspect that this claim is inflated to make the restaurant appear more exclusive and successful. A random sample of 30 customers yielded a sample average waiting time of 50 minutes.