document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=421212>Question 421212</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I am stumped with these two problems.  Can someone assist please and if possible, show your workings?\r<BR>\n" );
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document.write( "1.  Suppose that Z is a n(0,1) variable.  Which of the following statements is incorrect?<BR>\n" );
document.write( "a.  P(Z > 2.6) = P(Z < -2.6)<BR>\n" );
document.write( "b.  P(-0.8 < Z < 1.4) = 1 - P(Z > 1.4) - P(Z < -0.8)<BR>\n" );
document.write( "c.  P(Z > -2.8) = P(Z < 2.8)<BR>\n" );
document.write( "d.  P(Z < 0.74) = P(Z < -0.74)<BR>\n" );
document.write( "e.  P(Z > 0.0 = P(Z < 0.0)\r<BR>\n" );
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document.write( "2.  Of Z~n(0,1) with P(a < Z < 1.8) = 0.7800.  What is the value of a? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #294269 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=294269\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1. Suppose that Z is a n(0,1) variable. Which of the following statements is incorrect?<BR>\n" );
document.write( "a. P(Z > 2.6) = P(Z < -2.6)<BR>\n" );
document.write( "True: the area of the right tail = the area of the left tail.<BR>\n" );
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document.write( "b. P(-0.8 < Z < 1.4) = 1 - P(Z > 1.4) - P(Z < -0.8)<BR>\n" );
document.write( "True: the inbetween area = the whole area - the tails' areas.<BR>\n" );
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document.write( "c. P(Z > -2.8) = P(Z < 2.8)<BR>\n" );
document.write( "True: the right tail above -2.8 = the left tail below 2.8<BR>\n" );
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document.write( "d. P(Z < 0.74) = P(Z < -0.74)<BR>\n" );
document.write( "False: these two left tails are not equal<BR>\n" );
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document.write( "e. P(Z > 0.0 = P(Z < 0.0)<BR>\n" );
document.write( "True: Each probability is 1/2<BR>\n" );
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document.write( "2. Of Z~n(0,1) with P(a < Z < 1.8) = 0.7800. What is the value of a?<BR>\n" );
document.write( "Assume (1/2)(0.7800) = 0.3900 is between z = 0 and z=1.8<BR>\n" );
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document.write( "Find the z-value with a left tail of 0.5-0.39 = 0.11<BR>\n" );
document.write( "a = invNorm(0.11) = -1.2265<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
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