Download Spring 2013 ISE 2211 Statistics for Engineers Test Two Quizzes #6

Spring 2013 ISE 2211 Statistics for Engineers Test Two Quizzes #6 - #11
Quiz #6
1. Suppose the arrival of cars at a toll booth follows a Poisson Process with an average of 1.8 cars per 10
seconds. What is the probability of no cars arriving in 10 seconds?
Answer: 0.1653
2. Suppose the arrival of cars at a toll booth follows a Poisson Process with an average of 1.8 cars per 10
seconds. What is the probability of more than two cars arriving in 10 seconds?
Answer: 0.2694
3. Suppose the arrival of cars at a toll booth follows a Poisson Process with an average of 1.8 cars per 10
seconds. What is the probability of no cars arriving in 20 seconds?
Answer: 0.0273
Quiz #7
1. Suppose the mean time between failures for a CMOS battery is MTBF = 30,000 hours.
Given a CMOS battery that was randomly selected.
What is the probability that the battery will fail in less than 10,000 hours?
Answer: 0.2835
2. Suppose the mean time between failures for a CMOS battery is MTBF = 30,000 hours.
Given a CMOS battery that was randomly selected.
What is the probability that the battery will operate for a least 40,000 hours?
Answer: 0.2636
3. Suppose the mean time between failures for a CMOS battery is MTBF = 30,000 hours.
Given a CMOS battery that was randomly selected.
Determine the interval of time such that the probability the battery will not fail is 95%.
Answer: 1539 hours
Quiz #8
1. Given a Normal Distribution, calculate the probability (-1.17 < Z < +2.03)
Answer: 0.8578
2. Given a Normal Distribution, find z, such that P(-1.24 < Z < z) = 0.8
Answer: +1.33
Quiz #9
1. Suppose the measured value for carbon composite resistors is normally distributed with
Mean ? = 4700
Standard Deviation ? = 250
Given a sample size of 100 randomly selected resistors
What is the probability that the sample average is between 4675 and 4725 ?
Answer: 0.6828
Spring 2013 ISE 2211 Statistics for Engineers Test Two Quizzes #6 - #11
Quiz #10
1. A consumer product laboratory has been asked to determine the overall average number of calories per
serving for a new dessert.
The consumer testing laboratory reported the following results:
Sample Size = 36 servings
Sample Mean = 175 calories
Sample Standard Deviation = 12 calories
Estimate the overall average number of calories per serving for the new dessert product.
Use a 95% confidence interval.
Answer: mu = 175 +- 3.92
Quiz #11
1. Based on a sample of measured values, estimate the overall population mean (use a 95% confidence interval).
Sample Size = 16 servings
Sample Mean = 540 calories
Sample Standard Deviation = 80 calories
Answers:
For n = 16, should use t value (2.13) Answer: mu = 540 +/- 42.6
For Z value (1.96)
Answer: mu = 540 +/- 39.2