document.write( "Question 179649: 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? \n" ); document.write( "
Algebra.Com's Answer #134604 by stanbon(75887)\"\" \"About 
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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?
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\n" ); document.write( "p-hat = 1143/86991 = 0.01316...
\n" ); document.write( "E = 1.96*sqrt[0.01316*0.98684../86991] = 0.0003863
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\n" ); document.write( "95% CI: 0.01316-0.0003863 < p < 0.01316+0.0003863
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\n" ); document.write( "n is so large np > 5 and nq > 5.
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
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