document.write( "Question 693924: The head accountant at Raglan resources is concerned over the clerical errors on outgoing invoices and suspects that more than 20% of these invoices contain at least one error. In a random sample of 500 invoices, 120 are found to contain at least one error. Do these data support the account’s views? Let alpha=.05 \n" ); document.write( "

Algebra.Com's Answer #427629 by stanbon(75887) $\"\"$ $\"About$

You can put this solution on YOUR website!
The head accountant at Raglan resources is concerned over the clerical errors on outgoing invoices and suspects that more than 20% of these invoices contain at least one error. In a random sample of 500 invoices, 120 are found to contain at least one error. Do these data support the account’s views? Let alpha=.05
\n" ); document.write( "-------------------
\n" ); document.write( "Ho: p <= 0.20
\n" ); document.write( "Ha: p > 0.20 (claim)
\n" ); document.write( "--------
\n" ); document.write( "p-hat = 120/500 = 0.24
\n" ); document.write( "-----
\n" ); document.write( "z(0.24) = (0.24-0.20)/sqrt[0.20*0.80/500) = 2.2361
\n" ); document.write( "-----
\n" ); document.write( "P-value = P(z > 2.2361) = 0.0127
\n" ); document.write( "---------
\n" ); document.write( "Conclusion: Since the p-value is less than 5%, reject Ho.
\n" ); document.write( "The test results support the claim.
\n" ); document.write( "===================================
\n" ); document.write( "cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "

\n" );