3. A mark of at least 50 is required to pass a course. The marks this year run from a low of 45 to a high of 83, with a mean of 64 and a standard deviation of 5. The professor would like all students to pass, so he adjusts the marks to achieve a mean of 72 with a standard deviation of 5. Is this enough to ensure that all students will pass? (4 marks) 4. The average daily high in Port Forlom in July is found to have a mean of 25 .C with a standard deviation of 5 C. On how many days is the temperature expected to top 30 C, assuming a normal distribution? (3 marks) 5. A single burger contains a mean of 100 g of cooked beef with a standard deviation of 5 g. The restaurant owner claims that new triple burger contains three times as much beef. The table shows a sample of masses from 30 triple burgers. Does the sample support the claim at a 95% confidence level? (3 marks) Triple Burger Beef Mass (g) 292 297 295 290 290 294 291 296 282 291 289 291 290 292 295 289 289 294 298 292 294 295 285 297 296 287 302 289 290 290