MATH302 Week 3 Knowledge Check Homework Practice Questions

1. Question: Suppose a random variable, x, arises from a binomial experiment. If n = 14, and p = 0.13, find the standard deviation. Round answer to 4 decimal places. 2. Question: A coin is flipped 30 times. Find σ². Round to 1 decimal place. 3. Question: It is known that 50% of adult workers have a high school diploma. If a random sample of 6 adult workers is selected, what is the probability that 3 or more of them have a high school diploma? 4. Question: Suppose a random variable, x, arises from a binomial experiment. If n = 25, and p = 0.85, find the P(X = 15) using Excel. Round answer to 4 decimal places. 5. Question: If random variable X has a binomial distribution with n =10 and P(success) = p =0.6, find the probability that X is more than 3. (That is, find P(X>3) (round to 4 decimal places) 6. Question: The table shows a random sample of musicians and how they learned to play their instruments. Find P(musician is a male AND had studied in School). 7. Question: The number of M&M's for each color found in a case were recorded in the table below. Blue = 481, Brown = 371, Green = 483, Orange = 544, Red = 372, Yellow = 369 Total = 2620 What is the probability of selecting a red M&M? Round answer to 4 decimal places. 8. Question: How many different phone numbers are possible in the area code 503, if the first number cannot start with a 0 or 1? Do not use commas in your answer. 9. Question: In a box there are 3 red cards and 5 blue cards. The cards are well-shuffled. If you pick a card without looking at the box, what is the probability that you pick a red card? 10. Question: The random variable X = the number of vehicles owned. Find the probability that a person owns less than 2 vehicles. Round to two decimal places. 11. Question: Does the following table represent a valid discrete probability distribution? 12. Question: Let X be the number of courses taken by a part-time student at a college. The following table shows the probability distribution of X with probability as a percentage. What is the probability that a randomly selected part-time student at this college takes at least 2 courses? (That is, find P(X ≥ 2) 13. Question: The random variable X = the number of vehicles owned. Find the P(X > 2). Round to two decimal places. 14. Question: A coffee shop serves an average of 72 customers per hour during the morning rush. Find the probability that less than 59 customers arrive in an hour during tomorrow's morning rush. Round answer to 4 decimal places. 15. Question: If random variable X has a Poisson distribution with mean = 4.5, find the probability that X is more than 8. 16. Question: Computer Help Hot Line receives, on average, 14 calls per hour asking for assistance. Assume the variable follows a Poisson distribution. What is the probability that the company will receive more than 20 calls per hour? Round answer to 4 decimal places. 17. Question: A bank gets an average of 15 customers per hour. Assume the variable follows a Poisson distribution. Find the probability that there will be 11 or more customers at this bank in one hour. 18. Question: There are 4 accidents, on average, at an intersection. Assume the variable follows a Poisson distribution. Find the probability that there will be 5 or less accidents at this intersection. 19. Question: Three cards are drawn from a deck without replacement. What is the probability that all three cards are clubs? 20. Question: What type of probability uses sample spaces to determine the numerical probability that an event will occur?