| # | | Question | Helpful Rating | Tags |
| 350 |
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A robot, when working properly, produces 5% or less defective items. whenever the robot produces more than 5% defective items, i needs repair. A random sample of 300 items taken from the production line contained 27 defective items. Test at 1% significance level whether or not the robot needs repairing | | Continuity Correction, Normal Approximation, binomial |
| 319 |
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A machine cuts circular filters from large rolls of material. If 7.3% of the filters fail to meet specifications, use the normal approximation to the binomial to compute the probability that a sample of 100 of the filters will contain 5 or fewer that fail to meet specifications. | 100 | binomial, Binomial Probability, Normal Approximation, Continuity Correction |
| 287 |
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in a study of 11000 car crashes it was found that 5720 of them occurred within 5 miles of home. use a 0.01 significance level to test tha claim that more than 50% of car crashes occur within 5 miles of home. | | Binomial Probability, binomial, BINOMDIST |
| 269 |
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A classical experiment in extrasensory perception (ESP) consists of asking a subject to tell, without looking, the suit of each card in a deck of Zener cards. There are five suits in the deck so the probability of a chance match between the guess and the card is 1/5 or .20. If only chance is operating, you would expect a subject to get 20 matches in 100 guesses (.20 X 100 =20). The standard deviation for this mean of 20 is 4.
What is the probability of a subject making 23 or more matches in 100 guesses?
What is the probability of 27 or more matches in 100 guesses?
Suppose a friend of a friend claimed to have ESP and agreed to sit just on time and guess at 100 cards. Suppose she made 36 matches. Calculate the probability of this many, or more, matches if only chance is at work, and carefully write a conclusion. | | Z-Score, Binomial Probability, Normal Approximation, binomial, BINOMDIST |
| 209 |
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In 1992, the FAA conducted 86,991 pre-employment drug tests on job applicants who were to be engaged in safety and security relatd jobs and found that 1,143 were positive a. construct a 95% confidence interval for the population proportion of positive drug test. b. why is the normality assumption not a problem, despite the very small value? | 100 | Central Limit Theorem, binomial, Normal Approximation, Confidence Intervals |
| 199 |
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A local bakery determines that the probability of a customer ordering a blueberry muffin is 50%. 5 customers come into the bakery.
A. What is the probability that 3 out of the 5 order a blueberry muffin?
B. Explain why this scenario would meet the criteria of a binomial distribution.
A random sample of 100 students who took a statistics exam were asked their score on the exam. The mean score on the test was 50; the standard deviation was 10. The scores are normally distributed.
A) What percent of the students scored below 30?
B) What percent scored between 30 and 55? | | Binomial Probability, binomial |
| 175 |
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Suppose that in NY State, 35% of voters are Democrats, 30% are Republicans, and 11% are independent. You are conducting a poll by randomly calling registered voters. In your first four calls, what is the probability that you talk to:
a)all Republicans?
b)exactly 2 Republicans?
c)no Independents?
d)all Independents?
e)at least one independent? | 4.29 | Probability, Multiplication Rule, Binomial Probability, Choose, binomial |
