1. Binomial Probability

2. Sixty percent of all computer monitors sold by a large computer retailer have a flat panel display and 40% have a CRT display. The type of monitor purchased by each of the next 12 customers will be noted. Find the probability that exactly 6 will purchase a flat panel display. Define what a success is. What is the probability of a success? Binompdf(12,.6,6)=0.1766

3. Sixty percent of all computer monitors sold by a large computer retailer have a flat panel display and 40% have a CRT display. The type of monitor purchased by each of the next 12 customers will be noted. Find the probability that at most four will purchase a flat panel display. Binomcdf(12,.6,4)=0.0573

4. Sixty percent of all computer monitors sold by a large computer retailer have a flat panel display and 40% have a CRT display. The type of monitor purchased by each of the next 12 customers will be noted. Find the probability that less than four. Binomcdf(12,.6,3)=0.0153

5. Sixty percent of all computer monitors sold by a large computer retailer have a flat panel display and 40% have a CRT display. The type of monitor purchased by each of the next 12 customers will be noted. Find the probability that between 4 and 7 will purchase flat panel monitors. (inclusive) Binomcdf(12,.6,7) - Binomcdf(12,.6,3)=0.5466

6. Sixty percent of all computer monitors sold by a large computer retailer have a flat panel display and 40% have a CRT display. The type of monitor purchased by each of the next 12 customers will be noted. Find the mean, variance and standard deviation of the number of people that purchase flat panel displays. μ=7.2σ 2 =2.9σ=1.7

7. In recent years, homeowners have become increasingly security conscious. A Los Angeles Times poll reported that almost 20% of Southern California homeowners questioned had installed a home security system. Suppose that exactly 20% of all such homeowners have a system. Consider a random sample of 20 homeowners, find the probability that at least 8 have a security system. 1- Binomcdf(20,.2,7)=0.0321

8. Newsweek reported that one-third of all credit card users pay their bills in full each month. This figure is, of course, an average across different cards and issuers. Suppose that 30% of all individuals holding Visa cards issued by a certain bank pay in full each month. A random sample of 25 cardholders is to be selected. Find the mean, variance, and standard deviation of the number of cardholders that pay their bills in full each month. μ=7.5σ 2 =5.3σ=2.3

9. Suppose that in a certain metropolitan area 9 out of 10 households have a VCR. Calculate the probability that in a group of four households, exactly two would have a VCR. Binompdf(4,.9,2)=0.0486

10. Suppose that in a certain metropolitan area 9 out of 10 households have a VCR. Calculate the probability that in a group of four households all four would have a VCR. Binompdf(4,.9,4)=0.6561

11. According to a Los Angeles Times survey, the activity preferred by 80% of airline passengers on flights is sleeping. If 50 airline passengers are interviewed, find the probability that 45 prefer sleeping. Binompdf(50,.8,45)=0.0295

12. According to a Los Angeles Times survey, the activity preferred by 80% of airline passengers on flights is sleeping. If 50 airline passengers are interviewed, find the mean, variance, and standard deviation of the number that prefer sleeping. μ=40σ 2 =8σ=2.8

13. According to a Los Angeles Times survey, the activity preferred by 80% of airline passengers on flights is sleeping. If 50 airline passengers are interviewed, find the probability that at least 40 prefer sleeping. 1-Binomcdf(50,.8,39)=0.5836

14. Twenty-five percent of the customers entering a grocery store between 5PM and 7PM use an express checkout. Consider ten randomly selected customers, and let x denote the number among the ten who use the express checkout. Find P(x=2) What is P(x≤3) What is P(x≥4) Binompdf(10,.25,2)=0.2816 Binomcdf(10,.25,3)=0.7759 1-Binomcdf(10,.25,3)=0.2241