# stastics

posted by .

A survey of drivers in the United States found that 15% never use a cell phone while driving. Suppose that drivers arrive at random at an auto inspection station.
a. If the inspector checks 10 drivers, what is the probability that at least one driver never uses a cell phone while driving?
b. Suppose the inspector checks 1000 drivers. Use the normal approximation to the binomial distribution to find the approximate probability that at least 13% of these drivers never use a cell phone while driving.
c. If the drivers are inspected sequentially as they arrive randomly at the inspection station, what is the probability that the first driver who uses a cell phone while driving is the third driver checked?
d. What is the expected number of drivers who must be checked to find the first who never uses a cell phone while driving?
e. What is the expected number of drivers who must be checked to find the first driver who uses a cell phone while driving?
f. If it costs \$5 to question each driver, what is the expected cost and standard deviation of questioning up to and including the first driver who uses a cell phone while driving?
g. Will the cost of inspection in part f often exceed \$15? Explain.

## Similar Questions

1. ### Maths

"slow drivers" contribute to road rage problems and the police officer noticed that 2 of the 150 drivers in her survey caused problems for other drivers because of their slow speed. Use normal distribution and this information to describe …
2. ### drivers ed

I have to do a project and its for my drivers ed class. I chose to do Cell Phones and Driving. I need website sources but when I search for them I keep getting a bunch of articles talking about how that certain state or city has a …
3. ### statistics

twenty percent of drivers drining between 11pm and 3am are drunken drivers. using the binomial probabilities table. fine the problability that in a random sample of 12 drivers drining between 11 pm and 3am , two to four will be drunken …
4. ### Statisics

transportation officials tell us that 80% of drivers wear seat belt while driving. Find the probability that more then 567 drivers in a sample of 700 drivers wear seat belts
5. ### Stat

6% of american drivers read the newspaper while driving if 300 drivers are selected at random find the probability that between 15 and 25 say they read while driving
6. ### Math

The Pew Research Center recently polled n= 1048 U.S drivers andfound that 69% enjoyed driving their automobiles. (a) Construct a 95% confidence interval for the proportion of U.S.drivers who enjoy driving their automobiles. (b) In …
7. ### statistic

A survey of drivers in the United States found that 15% never use a cell phone while driving. Suppose that drivers arrive at random at an auto inspection station. a. If the inspector checks 10 drivers, what is the probability that …
8. ### Math

About 190 million drivers are registered in the United States. While on a trip with her family, a student counted the number of male drivers and female drivers on the road. There were 58 male drivers and 48 female drivers. Using the …
9. ### drivers' ed.

Are there some merge points where some drivers are entering while other drivers are exiting in close proximity?
10. ### drivers ed test

3. one way the national highway safety act helps drivers nationwide is by providing guidelines for maintenance on national highways requiring that all drivers have a federal drivers license providing drivers with insurance setting …

More Similar Questions