document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1118357>Question 1118357</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Dottie’s Tax Service specializes in tax returns for professional clients, such as physicians, dentists, accountants, and lawyers. A recent audit of the returns she prepared indicated that an error was made on 5.3 percent of the returns she prepared last year.<BR>\n" );
document.write( "Use the normal approximation to the binomial distribution to answer all parts of this question. Assuming this rate continues into this year and she prepares 66 returns, what is the probability that she makes errors on<BR>\n" );
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document.write( "a.	More than 6 returns? (Round z-score computation to 2 decimal places and the final answer to 4 decimal places.)<BR>\n" );
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document.write( "(i got 0.0495)\r<BR>\n" );
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document.write( "b.At least 6 returns? (Round z-score computation to 2 decimal places and the final answer to 4 decimal places.)<BR>\n" );
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document.write( "(i got 0.8643 and other answers but everything comes out wrong)<BR>\n" );
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document.write( "c.Exactly 6 returns? (Round z-score computation to 2 decimal places and the final answer to 4 decimal places.)\r<BR>\n" );
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document.write( "i know that here it is the answers b - a but i cant do this question without the answer to b <BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #733666 by </B><A HREF=/tutors/aboutme.mpl?userid=rothauserc><B>rothauserc(4718)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rothauserc><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=rothauserc><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=733666\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the mean is np = 66 * 0.053 = 3.498<BR>\n" );
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document.write( "standard deviation = square root(np(1-p)) = square root(3.498 * (1-0.053)) = 1.8201<BR>\n" );
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document.write( "a) Probability (P) (X>6) = 1 - P(X<=6) <BR>\n" );
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document.write( "z-score(X<=6) = (6-3.498)/1.8201 = 1.3746 approximately 1.37<BR>\n" );
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document.write( "P(X<=6) = 0.9147<BR>\n" );
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document.write( "Probability (P) (X>6) = 1 - 0.9147 = 0.0853<BR>\n" );
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document.write( "(b) P(X>=6) = P(X<=6.5) - P(X<=5.5) + P(X>6)<BR>\n" );
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document.write( "z-score(6.5) = (6.5-6)/1.8201 = 0.2747 approximately 0.27<BR>\n" );
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document.write( "P(X<=6.5) = 0.6064<BR>\n" );
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document.write( "z-score(5.5) = (5.5-6)/1.8201 = -0.2747 approximately -0.27<BR>\n" );
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document.write( "P(X<=5.5) = 0.3936<BR>\n" );
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document.write( "P(X>=6) = 0.6064 - 0.3936 + 0.0853 = 0.2981<BR>\n" );
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document.write( "(c) P(X=6) = P(X<=6.5) - P(X<=5.5) = 0.6064 - 0.3936 = 0.2128<BR>\n" );
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