document.write( "Question 193656: In 1992, the FAA conducted 94,575 pre-employment drug tests on job applicants who were to be engaged in safety and security-related jobs, and found that 2,145 were positive.
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\n" ); document.write( "(a) Construct a 99 percent confidence interval for the population proportion of positive drug tests.
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\n" ); document.write( "(b) Why is the normality assumption not a problem, despite the very small value of the observed proportion (p) \n" ); document.write( "
Algebra.Com's Answer #145356 by stanbon(75887)\"\" \"About 
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In 1992, the FAA conducted 94,575 pre-employment drug tests on job applicants who were to be engaged in safety and security-related jobs, and found that 2,145 were positive. \r
\n" ); document.write( "\n" ); document.write( "(a) Construct a 99 percent confidence interval for the population proportion of positive drug tests.
\n" ); document.write( "p-hat = 2145/94575 = 0.0227
\n" ); document.write( "E = 2.5758*sqrt[0.0227*0.9773/94575) = 0.0012
\n" ); document.write( "99% C.I.: 0.0227 - 0.0012 < p < 0.0227 + 0.0012
\n" ); document.write( "99% C.I.: 0.0215 < p < 0.02395
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\n" ); document.write( "\n" ); document.write( "(b) Why is the normality assumption not a problem, despite the very small value of the observed proportion (p)
\n" ); document.write( "The sample size is very large.
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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