document.write( "Question 471101: Please, please help! i am stuck on my statistics homework and could use the help to see and know how this is done for future assignments. \r
\n" ); document.write( "\n" ); document.write( "here is the assignment:\r
\n" ); document.write( "\n" ); document.write( "Resource: Statistics for Psychology
\n" ); document.write( "Prepare a written response to the following assignments located in the text:\r
\n" ); document.write( "\n" ); document.write( "• Ch. 1, Practice Problems: 12, 15, 19, 20, 21, and 22.\r
\n" ); document.write( "\n" ); document.write( "Note. Methods of computation may include the usage of Excel, SPSS™, Lotus®, SAS®, Minitab®, or by-hand computation.\r
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\n" ); document.write( "\n" ); document.write( "here is one of the questions:\r
\n" ); document.write( "\n" ); document.write( "15. Following are the speeds of 40 cars clocked by radar on a particular road in a
\n" ); document.write( "35-mph zone on a particular afternoon:
\n" ); document.write( "30, 36, 42, 36, 30, 52, 36, 34, 36, 33, 30, 32, 35, 32, 37, 34, 36, 31, 35, 20,
\n" ); document.write( "24, 46, 23, 31, 32, 45, 34, 37, 28, 40, 34, 38, 40, 52, 31, 33, 15, 27, 36, 40
\n" ); document.write( "Make (a) a frequency table and (b) a histogram. Then (c) describe the general
\n" ); document.write( "shape of the distribution.\r
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\n" ); document.write( "\n" ); document.write( "thank you so much in advance!\r
\n" ); document.write( "\n" ); document.write( "bridget \n" ); document.write( "
Algebra.Com's Answer #323219 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "The largest value is 52\r\n" );
document.write( "The smallest value is 15\r\n" );
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document.write( "We will make 6 classes:\r\n" );
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document.write( "To determine the class width\r\n" );
document.write( "1. Subtract 52-15 = 37\r\n" );
document.write( "2. Divide by 6. 37÷6 = 6.166666667\r\n" );
document.write( "3. Round to 6\r\n" );
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document.write( "The smallest class begins at the smallest number\r\n" );
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document.write( "1st class goes from 15 to 15+6 = 21\r\n" );
document.write( "2nd class goes from 22 to 22+6 = 28 \r\n" );
document.write( "3rd class goes from 29 to 29+6 = 35\r\n" );
document.write( "4th class goes from 36 to 36+6 = 42\r\n" );
document.write( "5th class goes from 43 to 43+6 = 49\r\n" );
document.write( "6th class goes from 50 to 50+6 = 56\r\n" );
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document.write( "Classes       frequencies\r\n" );
document.write( "15 - 21           2\r\n" );
document.write( "22 - 28           4\r\n" );
document.write( "29 - 35          17 \r\n" );
document.write( "36 - 42          13\r\n" );
document.write( "43 - 49           2   \r\n" );
document.write( "50 - 56           2\r\n" );
document.write( "----------------------\r\n" );
document.write( "Total            40\r\n" );
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document.write( "Make the histogram, starting and ending\r\n" );
document.write( "the bars halfway between the class bounds.\r\n" );
document.write( "I put the frequencies on top of the bars.\r\n" );
document.write( "(Your teacher may vary from this, as there\r\n" );
document.write( "is no standard way to do this. Some people\r\n" );
document.write( "put a vertical frequency axis.)\r\n" );
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document.write( "To determine if it is bell-shaped, we calculate the\r\n" );
document.write( "mean as 34.325 and the standard deviation as 7.325\r\n" );
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document.write( "1 standard deviation below the mean is 34.325 - 7.325 = 27\r\n" );
document.write( "1 standard deviation above the mean is 34.325 + 7.325 = 41.65\r\n" );
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document.write( "There are 21 values between those values, 21/40 = .775 = 77.5%\r\n" );
document.write( "That is within 10% of 68%, so that fits the first part of the\r\n" );
document.write( "criteria for being bell-shaped:\r\n" );
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document.write( "2 standard deviation below the mean is 34.325 - 2×7.325 = 19.6\r\n" );
document.write( "1 standard deviation above the mean is 34.325 + 2×7.325 = 48.9\r\n" );
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document.write( "There are 37 values between those values, 37/40 = .925 = 92.5%\r\n" );
document.write( "That is within 5% of 95%, so that fits the second part of the\r\n" );
document.write( "criteria of being bell-shaped.\r\n" );
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document.write( "So it is approximately bell-shaped.\r\n" );
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document.write( "Edwin

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