# MATHEMATICS

Question10 The taste test for PTC (phenylthiourea) is a common class demonstration in the study of genetics. It is known that 70% of the American people are “tasters” with the rest are “non-tasters”. Suppose a genetics class of size 20 does the test to see if they match the American percentage of “tasters” and “non-tasters”. Assume that the assignment of students to classes is a random process. Calculate the mean. 3 6 7 14 Question 11 The taste test for PTC (phenylthiourea) is a common class demonstration in the study of genetics. It is known that 70% of the American people are “tasters” with the rest are “non-tasters”. Suppose a genetics class of size 20 does the test to see if they match the American percentage of “tasters” and “non-tasters”. Assume that the assignment of students to classes is a random process. Calculate the variance. 4.2 5.5 8.4 9.3 Question 12 A quiz consists of 18 questions. Each question has 2 answer choices with exactly one correct answer. A student is completely unprepared for the quiz, so he guesses on all 18 questions. How many questions should the student expect to answer correctly? 6 8 9 12 18 Question 13 A quiz consists of 25 questions. Each question has 5 answer choices with exactly one correct answer. A student is completely unprepared for the quiz, so he guesses on all 25 questions. How many questions should the student expect to answer incorrectly? 1 5 10 15 20 Question 14 Car color preferences change over the years and according to the particular model that the customer selects. In a recent year, 20% of all luxury cars sold were white. Assume that 25 cars of that year and type are randomly selected. What is the definition of “success” in this binomial distribution application? The chosen luxury car is black. The chosen luxury car is not black. The chosen luxury car is not white. The chosen luxury car is white. Question 15 A medical association study shows that 20% of all Americans suffer from high blood pressure. Suppose that 10 Americans are randomly selected and each person is asked if he has high blood pressure. What is the probability of “success” in a single trial of this binomial distribution application? 10% 20% 50% 80% 90% Question 16 It is known that 10% of the customers in an electronics store purchase an MP3 player. A random sample of 30 customers is selected. Assume that the customers’ purchases are made independently. In this binomial distribution application, which Excel statement will find the probability of exactly 10 customers who purchase an MP3 player in this electronics store? =1- BINOMDIST(10,30,10%,TRUE) =1- BINOMDIST(10,30,10%,FALSE) =BINOMDIST(10,30,10%,TRUE) =BINOMDIST(10,30,10%,FALSE)