document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=366980>Question 366980</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hello Tutors, <BR>\n" );
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document.write( "a sample of 4 different calculators is randomly selected from a group containging 18 that are defective. and 35 with no defects. What is the probability that at least 1 calculator is defective. \r<BR>\n" );
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document.write( "I started with adding all calculators together to get a total of 53. Then I divided 1/52 since we are looking for at least 1 defect out of 4.   the answer I got was .0189.  Is this correct?  \r<BR>\n" );
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document.write( "If not, please solve and show your work. \r<BR>\n" );
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document.write( "Thank you kindly  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #261608 by </B><A HREF=/tutors/aboutme.mpl?userid=robertb><B>robertb(5830)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=robertb><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=robertb><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=261608\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1+-+%28%28matrix%282%2C1%2C18%2C0%29%29%2A%28matrix%282%2C1%2C35%2C4%29%29%29%2F%28%28matrix%282%2C1%2C53%2C4%29%29%29=0.82119 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >. How? The event that at least 1 calculator is defective is complementary with the event that no calculator is defective.  Hence <BR>\n" );
document.write( "P(at least 1 calculator is defective) = 1 - P(no calculator is defective).<BR>\n" );
document.write( "But  P(no calculator is defective) = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%28matrix%282%2C1%2C18%2C0%29%29%2A%28matrix%282%2C1%2C35%2C4%29%29%29%2F%28%28matrix%282%2C1%2C53%2C4%29%29%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >, and hence the answer above.  (Note: This is an example of a hypergeometric probability distribution.) </SPAN>\n" );
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