document.write( "Question 984258: an electricity company estimates that 60% of its customers pay their electricity bills within 15 days of delivery. a random sample of 400 bills indicated that 180 were paid within 15 days of delivery. at 0.10 level of significance is there evidence that the company's estimate is correct? \n" ); document.write( "

Algebra.Com's Answer #605586 by Fombitz(32388) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"p=180%2F400=0.45\"$
\n" ); document.write( " $\"SE=sqrt%28%28p%281-p%29%29%2FN%29=sqrt%28%280.45%29%280.55%29%29%2F400%29=0.02487\"$
\n" ); document.write( " $\"1.645%2A.02487=0.041\"$
\n" ); document.write( "So the 90% confidence interval would be,
\n" ); document.write( " $\"0.409%3Cp%3C0.491\"$
\n" ); document.write( "This is nowhere near the 60% the electric company estimates so evidence exists to reject the claim.
\n" ); document.write( " \n" ); document.write( "

\n" );