document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1104096>Question 1104096</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Assume that when adults with smartphones are randomly&#8203; selected, 41&#8203;% use them in meetings or classes. If 30 adult smartphone users are randomly&#8203; selected, find the probability that exactly 21 of them use their smartphones in meetings or classes.<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 #718836 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=718836\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> We use the binomial probability distribution to solve this problem<BR>\n" );
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document.write( "Probability (P) ( k successes in n trials) = nCk * p^k * (1-p)^(n-k), where nCk = n! / (k! * (n-k)!)<BR>\n" );
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document.write( "For this problem n = 30, k = 21, p = 0.41<BR>\n" );
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document.write( "P ( 21 use their smart phones out of 30 users ) = 30C21 * (0.41)^21 * (1 - 0.41)^(30-21)<BR>\n" );
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document.write( "P ( 21 use their smart phones out of 30 users ) = 0.0009<BR>\n" );
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