document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=169754>Question 169754</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Can you please show me how to do these two questions.<BR>\n" );
document.write( "1.  The time a group of high school students arrive home from  school each day was found to be normally distributed.  The mean time was 3:15 PM and the times had a standard deviation of 15 minutes.  What is the probability that a student chosen at random arrives home from school before 2:30 PM?<BR>\n" );
document.write( "2.  During a clothing sale, 1/4 of the store merchandise is reduced in price.  Find  the probability that 3 of 5 randomly-selected shirts have reduced prices.<BR>\n" );
document.write( "I have to show all my work.  Will you please help me.  <BR>\n" );
document.write( "Thank you </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #125135 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=125135\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1. The time a group of high school students arrive home from school each day was found to be normally distributed. The mean time was 3:15 PM and the times had a standard deviation of 15 minutes. What is the probability that a student chosen at random arrives home from school before 2:30 PM?<BR>\n" );
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document.write( "Find the z-score of 2:30 which is 45 minutes before 3:15.<BR>\n" );
document.write( "z(2:30) = (2:30 - 3:15)/15 = -45/15 = -3<BR>\n" );
document.write( "P(x < 2:30) = P(z<-3) = 0.00135<BR>\n" );
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document.write( "2. During a clothing sale, 1/4 of the store merchandise is reduced in price. Find the probability that 3 of 5 randomly-selected shirts have reduced prices.<BR>\n" );
document.write( "I have to show all my work. Will you please help me.<BR>\n" );
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document.write( "This is a binomial problem.<BR>\n" );
document.write( "n = 5, p = 1/4, x = 3<BR>\n" );
document.write( "P(x=3) = 5C3(1/4)^3*(3/4)^2 = 10*(9/4^5) = 0.08789..<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );