<PRE><B>Question 192516</B>
Probability Distribution
1. Decide whether the random variable is discrete or continuous.
a. The number of oil spills off the East Coast
discrete
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b. The number of touchdowns in the 2007 Super Bowl
discrete
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c. The temperature in degrees Fahrenheit on December 31 in New York City
continuous
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d. The blood pressure of Statistic student in a class one hour after the final exam
discrete
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e. The age of the youngest student in an English grammar class
discrete
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Binomial Probability 
Find the indicated binomial probabilities. Round to the nearest 3 decimal places. 
4. Hot Shot Battery manufactures batteries in batches of 15 with a defective rate of 10%

a. What is the probability that exactly 2 will be defective?
15C2(0.1)^2(0.9)^13 = 0.267
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b. What is the probability that between 2 and 4 inclusive will be defective?
binomcdf(15,0.1,4) - binomcdf(15,0.1,1) = 0.438
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c. What is the probability that no batteries will be defective?
(0.9)^15 = 0.206
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d. Find the mean &amp;#61549; 
np = 15*0.1 = 1.5
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e. Find the variance &amp;#61555;2
npq = 1.5*.9 = 1.35
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5. A Multiple-choice test has 15 questions with each having 4 possible answers with one correct. Assume a student answers every question.
 
a. What is the probability of getting exactly 5 correct answers? 
15C5(1/4)^5(3/4)^10 = 0.165
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b. What is the probability of getting less than 6 correct answers?
binomcdf(15,0.25,5) = 0.852
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Cheers,
Stan H. 

</PRE>