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10. Consider a probability model consisting of randomly drawing two colored ball

ID: 3364758 • Letter: 1

Question

10. Consider a probability model consisting of randomly drawing two colored balls without replacement from a jar containing 2 red and 3 blue balls. Now consider the event that exactly 1 out of the 2 balls is blue. What is P(A)? (d) 3/5 11. A multiple choice exam has 80 questions, each with four possible answers. If a student is junt guessing at all the answers, how many would we expect her to answer correctly? (a) 10 (b) 20 (c) 15 (d) 30 12. A continuous random variable may assume (a) all values in an interval or collection of intervals (b) only integer values in an interval or collection of intervals (c) only fractional values in an interval or oollection of intervals (d) all the positive integer values in an interval. For questions 13-16. In 2015 it is widely reported that 54% of all Americans older than 18 drink coffee daily. Suppose that in a random sample of 100 Americans older than 18, 62 said that they drink coffee every day. 13. The standard deviation of x is (a) 4.984 (b) 0.0025. (c) 24.84 (d) 0.0498. Version w

Explanation / Answer

10)P(A) =P(first is blue and second is red+first red and second blue)=(3/5)*(2/4)+(2/5)*(3/4)=3/5

option D

11)expected answers =np=80*(1/4) =20

option B

12)

option A is correct

13)

std deviation of x=(np(1-p))1/2 =4.984

option A