A professor wanted to estimate the average time spent studying among pre-med students at her school. She randomly sampled students and obtained a 99% confidence interval of (17.3, 22.5) hours/week. Which of the following would be true if the level of confidence was lowered to 95%? O a. More information is needed to determine what would happen to the width of the confidence interval. O b. The width of the confidence interval would be smaller. O c. The width of the confidence interval would be larger. O d. The width of the confidence interval would remain the same. Scientists discovered a new group of proteins in an animal species. They found that the distribution of the number of amino acids these proteins were made of was approximately normal with mean 530 and standard deviation 80. About what percent of these new proteins will be more than 690 amino acids long? O a. 16% O b. 5% O c. 2.5% Using the sample standard deviation s to estimate o introduces additional variation, so the t-distribution is spread out than the standard Normal distribution. O a. No More O b. Less O c. More A tire manufacturer claims that one particular type of tire will last at least 50,000 miles. A group of angry customers does not believe this is so. They take a sample of 14 tires to test if the mean mileage of the tires is really less than 50,000. If p-value = 0.015, what decision should be made if testing at the o = 0.05 level? O a. Do not reject Ho and conclude that the tires were not performing as claimed. O b. Reject Ho and conclude that the tires were not performing as claimed. O c. Reject Ho and conclude that the mean tire life really is 50,000 miles. O d. Do not reject Ho and conclude that the mean tire life really is 50,000 miles