..Note 2:
Although the probability distribution of a continuous r.v cannot be presented in tabular forms, we can have a formula in the form of a function represented by f(x) usually called the probability density functio..
Re: Probability using combination formula solution
Bayes' Theorem formulas an intuitive idea: we adjust our perspective (the probability set) given new, relevant information. Formally, Bayes' Theorem helps us move from an unconditional probability (what are the odds the economy will grow?) to a conditional probability (given new evidence, what are the odds the economy will grow?)
Question : I just really need to know which formulas to use to plug these numbers into. Obviously what I'm doing isn't working. I am really bad at math. Please help!
Based on past records, the probability is 0.7 that a person shopping at a certain store will spend less than $20.
a. What is the probability that 19 from a sample of 22 shoppers will spend less than $20?
b. What is the probability that at least 12 but not more than 17 from a sample of 22 shoppers will spend less than $20?
Answer : Hi, a) To find how many ways a group of 19 of 22 people could be chosen, do a combination of 22 people taken 19 at a time. This is 22 nCr 19 = 1,540 different combinations could be chosen as the 19 who spent less than $20. Then multiply this number times the probability (.7) of spending less than $20, raised to the number of people doing that(19), times the probability (.3) of spending more than $20, raised to the number of people doing that(3). So to find the probability that 109 of 22 people will spend less than $20 when the probability of that is .7 is: 22 nCr 19 *(.7)^19 * (.3)^3 = .0474 which is a 4.74% probability. b) To find the probability that at least 12 but not more than 17 from a sample of 22 shoppers will spend less than $20, we need to repeat the process above for each number from 12 to 17, and then add those results together. 22 nCr 12 *(.7)^12 * (.3)^10 = .05285 . 22 nCr 13 *(.7)^13 * (.3)^9 = .09486 22 nCr 14 *(.7)^14 * (.3)^8 = .14229 22 nCr 15 *.... More from Yahoo Answers
Answer : Hi, a) To find how many ways a group of 19 of 22 people could be chosen, do a combination of 22 people taken 19 at a time. This is 22 nCr 19 = 1,540 different combinations could be chosen as the 19 who spent less than $20. Then multiply this number times the probability (.7) of spending less than $20, raised to the number of people doing that(19), times the probability (.3) of spending more than $20, raised to the number of people doing that(3). So to find the probability that 109 of 22 people will spend less than $20 when the probability of that is .7 is: 22 nCr 19 *(.7)^19 * (.3)^3 = .0474 which is a 4.74% probability. b) To find the probability that at least 12 but not more than 17 from a sample of 22 shoppers will spend less than $20, we need to repeat the process above for each number from 12 to 17, and then add those results together. 22 nCr 12 *(.7)^12 * (.3)^10 = .05285 . 22 nCr 13 *(.7)^13 * (.3)^9 = .09486 22 nCr 14 *(.7)^14 * (.3)^8 = .14229 22 nCr 15 *.... More from Yahoo Answers
Question : The Binomial Probability Formula can be used to find the probability of 2 aces when drawing 4 cards without replacement from a deck.
True
False
Answer : False. --------- Attn: Without replacement means each time the event is not independent. The Binomial Probability Formula can be used to find the probability of 2 aces when drawing 4 cards with replacement from a deck... More from Yahoo Answers
Answer : False. --------- Attn: Without replacement means each time the event is not independent. The Binomial Probability Formula can be used to find the probability of 2 aces when drawing 4 cards with replacement from a deck... More from Yahoo Answers
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