STA 3024 Exam 1 Sample Questions

75. A study is conducted to investigate whether a diet including a particular food leads to increasedincidence of cancer. The results are as follows:CancerFood Yes No TotalYes 48 752 800No x 100Suppose we calculate, for the sample, the relative risk of cancer for people who eat the foodversus people who don’t. Which of the following values of x would yield a relative risk of atleast 2?(A) 2(B) 5(C) 8(D) all of the above76. Which of the following statements about a X 2 value of zero is true?(A) A X 2 value of zero means the population conditional distributions are the same.(B) A X 2 value of zero is very unlikely, even if the variables are independent.(C) A X 2 value of zero occurs if a cell has an observed count of zero.(D) A X 2 value of zero represents very strong evidence against H 0 .77. A chi-squared test for a table with two rows and three columns yields a test statistic value ofX 2 = 24.5. Which of the following statements are true?Statement I: This X 2 value represents evidence of a very strong association betweenthe two variables.Statement II: A X 2 value this large would be very unusual if the variables are independent.(A) Both Statement I and Statement II are true.(B) Statement I is true; Statement II is false.(C) Statement I is false; Statement II is true.(D) Both Statement I and Statement II are false.