Multiple choices related to the required probability.

1. Based on motor vehicle registration data, it is known that 40 percent of the passenger cars registered in New York has passenger side air bags. If an inspector visits a large shopping mall parking lot and selects 100 passenger cars at random which have New York registration, what is the probability that more than 50% of these vehicles have passenger side air bags?
1. Approximately 0.5%
2. Less than 0.1%
3. Approximately 10%
4. Approximately 2%

2. Which of the following is an ex of a discrete probability distribution?
a. Normal Distribution
b. Poisson Distribution
c. None of the above.
d. Exponential Distribution

3. While a process is in control, the variations in x-bar and R between different samples of the process output are caused by _____________.
i. natural variations
ii. Assignable causes
iii. Human error
iv. sampling bias

4. A marketing survey reports that 60% of respondents prefer cola to fruit soda. This is an ex of:
a. Estimate of the difference of two population proportions.
b. Estimate of a population mean.
c. Estimate of a population proportion.
d. Estimate of the difference of two population means.

5. So as to construct a confidence interval for a given estimate of a population mean based on a random sample, which Microsoft Excel function is used to determine the number of standard deviations of the sampling distribution to use for the upper and lower limits of the interval?
a. BINOMDIST
b. NORMSINV
c. STANDARDIZE
d. NORMDIST

6. Under what circumstances would we make use of the ASTM C-15 chart (partially reproduced on page 707 of the textbook) to set control limits for and x-bar or R chart?

a. When we have no prior knowledge of the variance of the process output variable we are studying.
b. When the number of units in each individual sample is small.
c. Either a or b.
d. When we cannot measure the process output variable with accuracy

7. A student applies to five different colleges. Each college has an admission rate of 20 percent, meaning that the college offers admission to 20 percent of those students who apply. What is the probability that the student will be rejected by all five schools?
a. Not enough information to determine.
b. Zero
c. 33%
d. 16%

Using BINOMDIST () in excel or 0.85 = 0.33

8. The Central Limit Theorem holds that the mean of a sampling distribution taken from a single population approaches the actual population mean as the number of samples increases.
a. True
b. False

In selecting simple random sample of size n from a normal population, the sampling distribution of the sample mean appropriated by a normal distribution as the sample size becomes large.

9. On the p chart, what process variable is plotted?
a. Sample means
b. range of the process variable observed in a sample
c. fraction of defective units in the sample
d. number of defects in a given unit of process output

10. What useful tool allows us to refine our previous estimate of the probability of an event given new observations?
a. The Normal Distribution
b. Bayes Theorem
c. The x-bar chart
d. The Central Limit Theorem