document.write( "Question 1141673: Find the P-value for the indicated hypothesis test.\r
\n" ); document.write( "\n" ); document.write( "A manufacturer claims that fewer than 8% of its products are defective. In a random sample of 120 such products, 12% are defective. Find the P-value for a test to support the manufacturer's claim.
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Algebra.Com's Answer #762329 by Boreal(15235)\"\" \"About 
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Given the assumptions of normality and randomness are present,
\n" ); document.write( "a one way test (fewer than 8% is one way) is a one sample proportion test with critical value z<-1.645. Note, 12% is not an integer, so one can use 14/120 as the nearest integer to 12% and 10/120 for the nearest integer to 8%. This is an important distinction in this kind of problem where exact per cents do not occur for specific numbers of people.
\n" ); document.write( "Here, it is done using per cents\r
\n" ); document.write( "\n" ); document.write( "z=(.08-.12)/sqrt(p*(1-p)/n)
\n" ); document.write( "=-0.04/sqrt (.08*.92/120)
\n" ); document.write( "=-0.04/0.0248
\n" ); document.write( "=-1.61
\n" ); document.write( "p-value is 0.0537
\n" ); document.write( "I suspect this is the value that is desired, but it is important to recognize that this is a discrete function here and not continuous.\r
\n" ); document.write( "\n" ); document.write( "Here, it is done using integers closest to the given per cents
\n" ); document.write( "z=(10-14)/120/sqrt (10/120)(110/120)/120
\n" ); document.write( "=-0.03333/0.0252
\n" ); document.write( "=-1.32 p-value is 0.0934\r
\n" ); document.write( "\n" ); document.write( "And if one wishes for an exact result, the binomial formula may be used.
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