document.write( "Question 1020389: 1.Suppose we are flipping a fair coin (i.e., probability of heads = .5 and probability of tails = .5). What is the probability that in a sample of 5 flips, fewer than 4 will be heads?\r
\n" ); document.write( "\n" ); document.write( "2.The U.S. mint, which produces billions of coins annually, has a mean daily defect rate of 4 coins. Let X be the number of defective coins produced on a given day.\r
\n" ); document.write( "\n" ); document.write( "What is the variance of this distribution?\r
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\n" ); document.write( "\n" ); document.write( "3. Consider the following discrete distribution. Note that x represents the value of a particular outcome and P(x) represents the probability of that outcome.\r
\n" ); document.write( "\n" ); document.write( "x P(x)
\n" ); document.write( "0 0.1
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\n" ); document.write( "2 0.3
\n" ); document.write( "3 0.2
\n" ); document.write( "4 0.1
\n" ); document.write( "5 0.1
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\n" ); document.write( "\n" ); document.write( "What is the probability that an observed x is less than or equal to 3?
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Algebra.Com's Answer #636309 by robertb(5830)\"\" \"About 
You can put this solution on YOUR website!
1. The statistical experiment follows the binomial distribution, with pmf \"p%28x%29+=+C%285%2Cx%29%2A0.5%5E%285-x%290.5%5Ex+=+C%285%2Cx%290.5%5E5\". The answer is p(0) + p(1) + p(2) + p(3). But an easier way is to evaluate 1-p(4)-p(5) = 1-\"%28C%285%2C4%29%2BC%285%2C5%29%29%2A0.5%5E5+=+6%2A0.5%5E5\" = 1-3/16 = 13/16 = 0.8125.\r
\n" ); document.write( "\n" ); document.write( "3. The answer is p(0) + p(1) + p(2) + p(3), but it is easier to compute 1- p(4)-p(5) = 1-0.1 - 0.1 = 0.8.
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