document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1142019>Question 1142019</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The owner of a computer repair shop has determined that their daily revenue has mean $7200 and standard deviation $1200. The daily revenue totals for the next 30 days will be monitored. What is the probability that the mean daily revenue for the next 30 days will be between $7000 and $7500?<BR>\n" );
document.write( "A) 0.8186 <BR>\n" );
document.write( "B) 0.2667<BR>\n" );
document.write( "C) 0.7333<BR>\n" );
document.write( "D) 0.9147 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #762688 by </B><A HREF=/tutors/aboutme.mpl?userid=VFBundy><B>VFBundy(438)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=VFBundy><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=VFBundy><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=762688\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> SD of the sample = SD of the population divided by the square root of the number of items in the sample:<BR>\n" );
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document.write( "SD of the sample = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1200%2Fsqrt%2830%29 ALIGN=MIDDLE  ALT=\"1200%2Fsqrt%2830%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=219.09 ALIGN=MIDDLE  ALT=\"219.09\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "Take 7500 and subtract the mean of 7200 to get a result of 300.  Divide 300 by the SD of the sample (219.09) to get a result of 1.37.  Look up +1.37 on a z-table to get a result of 0.9147.  This means there is a 0.9147 probability that the mean daily revenue for the next 30 days will be below $7500.<BR>\n" );
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document.write( "Take 7000 and subtract the mean of 7200 to get a result of -200.  Divide -200 by the SD of the sample (219.09) to get a result of -0.91.  Look up -0.91 on a z-table to get a result of 0.1814.  This means there is a 0.1814 probability that the mean daily revenue for the next 30 days will be below $7000.<BR>\n" );
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document.write( "To find out the probability that the mean daily revenue for the next 30 days will be between $7000 and $7500, simply subtract the probability that the mean daily revenue is less than $7000 (0.1814) from the probability that the mean daily revenue is less than $7500 (0.9147) to get a result of 0.7333.<BR>\n" );
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document.write( "So, the answer is (C). </SPAN>\n" );
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