Question 383202:  I don't see my catagory. It is about permutations. My book is not giving me clear answers. I need to find the number of permutations for: 1,3,5? and another is: 7P3? Thank you. 
 Found 2 solutions by  jim_thompson5910, moncherie1: Answer by jim_thompson5910(35256)      (Show Source): 
You can  put this solution on YOUR website! The set of permutations of {1,3,5} is simply the set of all possible ways of arranging {1,3,5}. These are
 
 
{1,3,5}, {1,5,3}, {3,1,5}, {3,5,1}, {5,1,3}, {5,3,1}
 
 
Since there are 6 items in this collection, this means that there are 6 permutations.
 
 
 
A quick way of computing this is to simply calculate 3! to get 3! = 3*2*1 = 6
 
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Recall that 
 
 
n P r = (n!)/(n-r)!
 
 
So in this case, n = 7 and r = 3, which means that 
 
 
7 P 3 = (7!)/(7-3)! = (7*6*5*4!)/(4!) = 7*6*5 = 210
 
 
 
So 7 P 3 = 210 
 Answer by moncherie1(1)      (Show Source): 
You can  put this solution on YOUR website! 8.62 In 1992, the FAA conducted 86,991 pre-employment drug tests on job applicants who were to be 
engaged in safety and security-related jobs, and found that 1,143 were positive. (a) Construct a 
95 percent confidence interval for the population proportion of positive drug tests. (b) Why is the 
normality assumption not a problem, despite the very small value of p? (Data are from Flying 120, 
no. 11 [November 1993], p. 31.) 
 
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