document.write( "Question 1204309: Find the indicated probability given that Z is a random variable with a standard normal distribution. (Round your answer to four decimal places.)
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document.write( "P(0 ≤ Z ≤ 1.23)
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document.write( "P(0 ≤ Z ≤ 1.23) = \n" );
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Algebra.Com's Answer #840486 by math_tutor2020(3817)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Answer: 0.3907\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Explanation\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "There are a few methods we could use.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Method 1 is to use a Z table such as this \n" ); document.write( "https://www.ztable.net/ \n" ); document.write( "to find that \n" ); document.write( "P(Z < 0.00) = 0.5 \n" ); document.write( "P(Z < 1.23) = 0.89065\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So, \n" ); document.write( "P(a < Z < b) = P(Z < b) - P(Z < a) \n" ); document.write( "P(0 < Z < 1.23) = P(Z < 1.23) - P(Z < 0) \n" ); document.write( "P(0 < Z < 1.23) = 0.89065 - 0.5 \n" ); document.write( "P(0 < Z < 1.23) = 0.39065 \n" ); document.write( "P(0 < Z < 1.23) = 0.3907\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Method 2 involves a calculator such as this one \n" ); document.write( "https://davidmlane.com/normal.html \n" ); document.write( "The mean and standard deviation are 0 and 1 respectively. \n" ); document.write( "Click the \"between\" and fill in the values 0 and 1.23 to have 0.3907 show up.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Another calculator you can use is a TI83 or TI84. \n" ); document.write( "Refer to this article. \n" ); document.write( "https://www.statology.org/normal-probabilities-ti-84-calculator/ \n" ); document.write( "Use the normalCDF function to get the area under the curve. \n" ); document.write( "The input that you'll type in is: normalCDF(0,1.23) \n" ); document.write( "Or optionally you could type in normalCDF(0,1.23,0,1) \n" ); document.write( "The TI84 should display the approximate result 0.3906513828 which rounds to 0.3907\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Or you could use a spreadsheet. \n" ); document.write( "The spreadsheet function you'll use is called normDist \n" ); document.write( "Refer to this page for more info \n" ); document.write( "https://www.statology.org/normal-distribution-probability-excel/\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Yet another method is WolframAlpha \n" ); document.write( "Type in P(0 < z < 1.23) and you should get roughly 0.390651 which rounds to the answer shown above. \n" ); document.write( "Caution: WolframAlpha is a great resource, but it has a glaring flaw. The graph shown on the page is not correct. The normal distribution curve should be entirely above the x axis. I don't know why some parts of it are below the x axis. I would hope the people running that website would fix the error soon. Rely on the diagram produced by the davidmlane website.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " ![]() \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " ![]() \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "As you can see, there are a lot of ways to calculate the normal distribution probabilities. \n" ); document.write( "Feel free to explore other options. \n" ); document.write( " \n" ); document.write( " |