Statistics Homework. Multiple choice, one answer.

Problems 13 and 14 refer to the following table: The New York City Police Department tracks the number of vehicles involved in each vehicle collision in Manhattan. The table shows the probability distribution for the number of vehicles (x) involved in collisions in Manhattan in July 2015. Number of Vehicles (x) Probability 0.097 0.871 0.004 0.001 13. Determine the probability that 3 vehicles are involved in a collision so that this data set represents a legitimate probability distribution. A. 0.181 B. 0.081 C. 0.027 D. 0.004 14. Determine the expected number (mean) of vehicles involved in a collision. A. 3.000 B. 1.941 C. 2.500 D. 0.200 15. In your drawer you have 10 white socks, 6 black socks, 4 brown socks and 2 blue socks. Your roommate is still asleep, and you cannot turn the light on while you get dressed. You reach in blindly and grab two socks. What is the probability of pulling out a matching pair of black socks? A. (0/22 + 5/21) C. (9/22.5/21) B. ( 6/22:6/22) D. (6/22 + 6/21 ) 16. A flight from New York to Indianapolis takes less than 2 hours 75% of the time. What is the probability of randomly selecting 3 flights from New York to Indianapolis and none of them take less than 2 hours? (Rounded to three decimals.) A. 0.25 B. 0.578 C. 0.422 D. 0.016 17. Assume that random guesses are made for 40 multiple choice questions on the Statistics final test and that there are 4 choices on each question with the probability of success 0.25. Find the probability that the student will pass the test by answering at least 20 questions correctly (This problem meets all the requirements of a binomial situation and the following choices are given in a rounded percentage form.) A. 50% B. 0.04% C. 99.94% D. 0.06%