document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=445516>Question 445516</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A safety light is designed so that the times between flashes are normally distributed with a mean of 4.00 seconds and a standard deviation of .50 seconds.<BR>\n" );
document.write( "a. Find the probability that an individual time is greater than 4.50 seconds<BR>\n" );
document.write( "b. Find the probability that the mean for 50 randomly selected times is greater than 4.50 seconds<BR>\n" );
document.write( "c. Is part a or b more significant (being light) due to the importance of a sample OR SINGLE strobe?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #306883 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=306883\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A safety light is designed so that the times between flashes are normally distributed with a mean of 4.00 seconds and a standard deviation of .50 seconds.<BR>\n" );
document.write( "a. Find the probability that an individual time is greater than 4.50 seconds<BR>\n" );
document.write( "----<BR>\n" );
document.write( "z(4.5) = (4.5-4)/0.5 = 1<BR>\n" );
document.write( "P(x >4.5) = P(z > 1) = 0.1587<BR>\n" );
document.write( "-------------------------------------<BR>\n" );
document.write( "b. Find the probability that the mean for 50 randomly selected times is greater than 4.50 seconds<BR>\n" );
document.write( "z(4.5) = (4.5-4)/[0.5/sqrt(50)} = 7.0711<BR>\n" );
document.write( "P(x > 4.5) = P(z > 7.0711) = 7.737x10^-13<BR>\n" );
document.write( "------------------------------------- <BR>\n" );
document.write( "c. Is part a or b more significant (being light) due to the importance of a sample OR SINGLE strobe?<BR>\n" );
document.write( "I don't understand that question.<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" );