document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1189821>Question 1189821</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Emergency Room Tests The frequency distribution shows the number of medical tests conducted on<BR>\n" );
document.write( "30 randomly selected emergency room patients.<BR>\n" );
document.write( " Age 19 and under Age 20<BR>\n" );
document.write( "Age 21<BR>\n" );
document.write( "Source: World Almanac.<BR>\n" );
document.write( "Male Female<BR>\n" );
document.write( "4746 4517 1625 1553 1679 1627<BR>\n" );
document.write( "Choose one driver at random. Find the probability that the driver is<BR>\n" );
document.write( "a. Male and 19 years or under<BR>\n" );
document.write( "b. Age 20 or female<BR>\n" );
document.write( "c. At least 20 years old </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #849262 by </B><A HREF=/tutors/aboutme.mpl?userid=CPhill><B>CPhill(1987)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=CPhill><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=CPhill><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=849262\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Here's how to calculate the probabilities:\r<BR>\n" );
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document.write( "First, let's organize the data into a contingency table:\r<BR>\n" );
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document.write( "| Age Group | Male | Female | Total |<BR>\n" );
document.write( "|---|---|---|---|<BR>\n" );
document.write( "| 19 and under | 4746 | 4517 | 9263 |<BR>\n" );
document.write( "| 20 | 1625 | 1553 | 3178 |<BR>\n" );
document.write( "| 21 | 1679 | 1627 | 3306 |<BR>\n" );
document.write( "| Total | 8050 | 7697 | 15747 |\r<BR>\n" );
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document.write( "*Total number of patients = 15747\r<BR>\n" );
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document.write( "Now, let's calculate the probabilities:\r<BR>\n" );
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document.write( "**a. Male and 19 years or under:**\r<BR>\n" );
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document.write( "*   Number of patients who are male and 19 or under: 4746<BR>\n" );
document.write( "*   Total number of patients: 15747<BR>\n" );
document.write( "*   Probability: 4746 / 15747 ≈ 0.3014\r<BR>\n" );
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document.write( "**b. Age 20 or female:**\r<BR>\n" );
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document.write( "*   Number of patients age 20: 3178<BR>\n" );
document.write( "*   Number of female patients: 7697<BR>\n" );
document.write( "*   Number of patients who are age 20 *and* female: 1553<BR>\n" );
document.write( "*   Number of patients who are age 20 *or* female = (Number of age 20) + (Number of female) - (Number of age 20 and female) = 3178 + 7697 - 1553 = 9322<BR>\n" );
document.write( "*   Probability: 9322 / 15747 ≈ 0.5920\r<BR>\n" );
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document.write( "**c. At least 20 years old:**\r<BR>\n" );
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document.write( "*   Number of patients age 20: 3178<BR>\n" );
document.write( "*   Number of patients age 21: 3306<BR>\n" );
document.write( "*   Number of patients at least 20 years old: 3178 + 3306 = 6484<BR>\n" );
document.write( "*   Probability: 6484 / 15747 ≈ 0.4118<BR>\n" );
document.write( " </SPAN>\n" );
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