What are the answers for the problems below? please give me explanations as well. please ignore the random line or number. thank you. this is from cliff ap statistics book

26- 27 28, 29, For a set of exam scores, the mean was 68, and the standard deviation was 12. If 10 points is added to every test score, what will be the new mean and standard deviation of the exam scores? A. Mean 68 and standard deviation 12 B. Mean 78 and standard deviation 12 C. Mean 68 and standard deviation 15.16 D. Mean 78 and standard deviation 15.16 E. Mean 78 and standard deviation 22 Suppose that events A and B are independent events. Also, the P(A) =0.34 and the P(B) = 0.15. What would be the P(A or B)? A. 0.051 B. 0.24] C. 0439 D. 0.490 E. 0.541 A hotel desires that the temperature of their party ballroom be 72 degrees Fahrenheit at all times. In order to test whether this is the case, the hotel manager decides (o take temperature measurements at 40 random times during the course of the week and then to use the sample mean and sample deviation to test a claim concerning the true mean temperature of the ballroom. Which of the following would be the most appropriate null and alternate hypothesis for this test? A. H,: p=72 degrees, H,: g > 72 degrees B. H; p=72degrees, H;: j1 72 degrees E. H,: 272 degrees, H;: n