SOLUTION: A manufacturer knows that their items have a normally distributed length, with a mean of 14.3 inches, and standard deviation of 1.7 inches.
If 12 items are chosen at random, wha
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-> SOLUTION: A manufacturer knows that their items have a normally distributed length, with a mean of 14.3 inches, and standard deviation of 1.7 inches.
If 12 items are chosen at random, wha
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Question 1200840: A manufacturer knows that their items have a normally distributed length, with a mean of 14.3 inches, and standard deviation of 1.7 inches.
If 12 items are chosen at random, what is the probability that their mean length is less than 14.2 inches?
Enter your answers as numbers accurate to 4 decimal places.
You can put this solution on YOUR website! mean is 14.3
sandard deviation is 1.7
sample size is 12.
standard error is 1.7 / sqrt(12) = .4907477288.
probability that their mean length is less than 14.2 would be .4193 using the online calculator at https://davidmlane.com/hyperstat/z_table.html
the probability is .4192663762 using the ti-84 plus scientific calculator.
here's what the results look like using the online calculator.
the key is that you have to use the standard error, rather than the standard deviation, because you are looking for the mean of a sample of size greater than 1.
