document.write( "Question 1182375: The Precision Scientific Instruments company manufactures thermometers that
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document.write( "are supposed to read 0
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document.write( "𝑜𝐶 at the freezing point of water. Tests on these
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document.write( "instruments revealed that at the freezing point of water some thermometers
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document.write( "give readings above zero degrees Celsius while other thermometers give
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document.write( "readings below zero degrees Celsius with an average of zero degrees Celsius
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document.write( "and a standard deviation of the readings ion 0.9
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document.write( "𝑜𝐶. Assume that the readings are
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document.write( "normally distributed,
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document.write( "i. Find the probability of observing one thermometer at random whose
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document.write( "reading is between +𝟎. 𝟓𝒐𝑪 and +𝟏. 𝟔𝒐𝑪 at the freezing point of water. \n" );
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Algebra.Com's Answer #812433 by math_tutor2020(3817) ![]() You can put this solution on YOUR website! \n" ); document.write( "x = temperature in degrees Celsius \n" ); document.write( "mu = 0 = population mean temperature in degrees C \n" ); document.write( "sigma = 0.9 = population standard deviation for the temperatures\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Convert x = 0.5 to a corresponding z score \n" ); document.write( "z = (x-mu)/sigma \n" ); document.write( "z = (0.5-0)/0.9 \n" ); document.write( "z = 0.56 approximately\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Do the same for x = 1.6 \n" ); document.write( "z = (x-mu)/sigma \n" ); document.write( "z = (1.6-0)/0.9 \n" ); document.write( "z = 1.78 approximately\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Your teacher is asking you to find P(0.5 < x < 1.6) which is roughly equivalent to P(0.56 < z < 1.78) based on those earlier z score conversions.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now use a z table such as this one \n" ); document.write( "https://www.ztable.net/ \n" ); document.write( "or one you would find in the back of your textbook. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "From that table, we see the following approximations \n" ); document.write( "P(z < 0.56) = 0.71226 \n" ); document.write( "P(z < 1.78) = 0.96246 \n" ); document.write( "which are found as shown below \n" ); document.write( " ![]() \n" ); document.write( "the stuff in red pertains to z = 0.56, while the stuff in blue is for z = 1.78\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Then we subtract those values to get the answer we're after \n" ); document.write( "P(a < z < b) = P(z < b) - P(z < a) \n" ); document.write( "P(0.56 < z < 1.78) = P(z < 1.78) - P(z < 0.56) \n" ); document.write( "P(0.56 < z < 1.78) = 0.96246 - 0.71226 \n" ); document.write( "P(0.56 < z < 1.78) = 0.2502 \n" ); document.write( "P(0.5 < x < 1.6) = 0.2502\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer: Approximately 0.2502 \n" ); document.write( "Use a calculator to get more accuracy.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "There's roughly a 25.02% chance of getting a reading between 0.5 degrees C and 1.6 degrees C (when the true reading should be 0 degrees C). \n" ); document.write( " \n" ); document.write( " |