SOLUTION: Use the following information to answer the following four questions: The error in taking various measurements of a rod is normally distributed with mean 17 in and standard deviati
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-> SOLUTION: Use the following information to answer the following four questions: The error in taking various measurements of a rod is normally distributed with mean 17 in and standard deviati
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Question 1119558: Use the following information to answer the following four questions: The error in taking various measurements of a rod is normally distributed with mean 17 in and standard deviation 3.1 in.
27. What is the probability that a randomly selected measurement will be between 15 in and 19 in?
(a) 0.5123
(b) 0.4811
(c) 0.3956
(d) 0.2997
(e)
28. What is the probability that a randomly selected measurement will be less than 22 in?
(a) 0.9466
(b) 0.8675
(c) 0.7765
(d) 0.6875
29. What is the probability that a randomly selected measurement will be greater than 14.3 in?
(a) 0.9697
(b) 0.9090
(c) 0.8081
(d) 0.7885
30. A randomly selected measurement was found to be in the top 5%. What was its value?
(a) 24.08
(b) 23.07
(c) 22.09
(d) 21.06
use of a calculator such as this is doing it the easy way.
you don't have to convert to z-scores and you don't have to look up values in the z-score table and you don't have to interpolate when the area to the left of a z-score is not exactly as the areas found in the z-score tables.
the answers i got are very close to the correct answers, but they appear to be off by a digit.
i checked with the TI-84 Plus that can do the same calculations easily and found that your selections are the ones that are off.
it appears that they truncated to 4 decimal digits rather than rounding to 4 decimal digits.
for example, the answer i got for the first problem is .48117 which rounds to .4812.
the answer i got for the second problem was consistent with the selection, therefore no discrepancy there.
the answer i got for the third problem was consistent with the selection, therefore no discrepancy there.
the answer i got for the fourth problem was 22.099 which rounds to 22.1.
the selection said 22.09 so it appears they truncated rather than rounded there as well.
regardless, the answers i got were still closer to those selections than any of the other selections so it was reasonable to assume those selections were the ones they were looking for.