Probability Questions 2B
Not what you're looking for?
11. Which probability is greater? A: Prob (person is a CEO of a company | person is a male). B: Prob (person is a male | person is a CEO of a company)
a. A b. B c. equally likely
12. The number of raisins in boxes of cereal is normally distributed with a mean of 112 and a standard deviation of 15 raisins. Using the table, what is the probability that a box will have less than 132 raisins in it.
a. 95% b. 41% c. 84% d. 91
b.
13. A die is rolled 3,000 times and the number of 5's and 6's together is noted. What is the approximate probability that the total number of 5's and 6's together is greater than 1,052? (This is a binomial situation; a roll results in a 5 or a 6, or it doesn't. Approximate it with a normal distribution and use its standard deviation.)
a. 13.5% b. 16% c. 2.5% d. .015%
14. Factory I produces 40% of the light bulbs in a certain country. Factory II produces 50% and Factory III produces the remaining 10% of them. If 2% of Factory I's light bulbs are defective, 4% of Factory II's light bulbs are defective, and 12% of Factory III's bulbs are defective, what percent of all the light bulbs are defective?
a. 3.2% b. 4.0% c. 2.8% d. 4.2%
15. If a light bulb is randomly selected and found to be defective, what is the probability it was produced by Factory III?
a. 22.2% b. 18.6% c. 30.0% d. 38.2%
16. For a random variable X with mean μ and standard deviation σ, the standard normal z is equal to
a. (X-σ)/μ b. (X-μ)/σ c. (X-μ)/(σ^2) d. μX/σ
17. Pick three numbers at random between 1 and 100 inclusive. What is the probability they're all are between 71 and 82 inclusive.
a. .36 b. .001728 c. .363 d. none of these
18. Roll a pair of dice. If you win $100 for rolling a 12, win $10 for rolling a number less than 7, and lose $4 for rolling anything else, what are your expected winnings per play? What are your expected winnings if you play this game 500 times?
a. $1.94 b. $4.72 c. $2.88 d. -$.68
19. Spin a dial 20 times. If the probability of landing on the A sector is .20, and the probability of landing on the B sector is .55, and the probability of landing on the C sector is .25, what is the probability of landing A 4 times, on B 11 times, and C 5 times?
a. [20!/(4!11!5!)].204.5511.255 b. .20*4*.55*11*.25*5 c. Not enough info
20. Scores on a test are normally distributed with mean 500 and standard deviation 50. What is the probability a score will be between 520 and 550?
a. 19.8% b. 18.6% c. 24.1% 15.2%
Purchase this Solution
Solution Summary
Step-by-step solutions are provided in text format and Word format.
Solution Preview
11. Which probability is greater? A: Prob (person is a CEO of a company | person is a male). B: Prob (person is a male | person is a CEO of a company)
a. A b. B c. equally likely
Most CEOs are male, but most males are not CEOs.
12. The number of raisins in boxes of cereal is normally distributed with a mean of 112 and a standard deviation of 15 raisins. Using the table, what is the probability that a box will have less than 132 raisins in it.
a. 95% b. 41% c. 84% d. 91%
z = (132 - 112) / 15 = 1.33
From the table, this is 91%.
13. A die is rolled 3,000 times and the number of 5's and 6's together is noted. What is the approximate probability that the total number of 5's and 6's together is greater than 1,052? (This is a binomial situation; a roll results in a 5 or a 6, or it doesn't. Approximate it with a normal distribution and use its standard deviation.)
a. 13.5% b. 16% c. 2.5% d. .015%
n = 3000
p = 2/6 = 1/3
q = 4/6 = 2/3
mean = np = 3000 * 1/3 = 1000 ...
Education
- MSc, California State Polytechnic University, Pomona
- MBA, University of California, Riverside
- BSc, California State Polytechnic University, Pomona
- BSc, California State Polytechnic University, Pomona
Recent Feedback
- "Excellent work. Well explained."
- "Can you kindly take a look at 647530 and 647531. Thanks"
- "Thank you so very much. This is very well done and presented. I certainly appreciate your hard work. I am a novice at statistics and it is nice to know there are those out there who really do understand. Thanks again for an excellent posting. SPJ"
- "GREAT JOB!!!"
- "Hello, thank you for your answer for my probability question. However, I think you interpreted the second and third question differently than was meant, as the assumption still stands that a person still independently ranks the n options first. The probability I am after is the probability that this independently determined ranking then is equal to one of the p fixed rankings. Similarly for the third question, where the x people choose their ranking independently, and then I want the probability that for x people this is equal to one particular ranking. I was wondering if you could help me with this. "
Purchase this Solution
Free BrainMass Quizzes
Measures of Central Tendency
Tests knowledge of the three main measures of central tendency, including some simple calculation questions.
Know Your Statistical Concepts
Each question is a choice-summary multiple choice question that presents you with a statistical concept and then 4 numbered statements. You must decide which (if any) of the numbered statements is/are true as they relate to the statistical concept.
Measures of Central Tendency
This quiz evaluates the students understanding of the measures of central tendency seen in statistics. This quiz is specifically designed to incorporate the measures of central tendency as they relate to psychological research.
Terms and Definitions for Statistics
This quiz covers basic terms and definitions of statistics.