(Ch.4, Q.9) need answers: A sample of concrete specimens of a certain type is se
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(Ch.4, Q.9) need answers:A sample of concrete specimens of a certain type is selected, and the compressive strength of each specimen is determined. The mean and standard deviation are calculated as x = 7000 and s = 300, and the sample histogram is found to be well approximated by a normal curve. (a)Approximately what percentage of the sample observations are between 6700 and 7300? (Round the answer to the nearest whole number.) Approximately %
(b) Approximately what percentage of sample observations are outside the interval from 6400 to 7600? (Round the answer to the nearest whole number.) Approximately %
(c) What can be said about the approximate percentage of observations between 6400 and 6700? (Round the answer to the nearest whole number.) Approximately %
(d) Why would you not use Chebyshev's Rule to answer the questions posed in parts (a)-(c)? 1. Chebyshev's Rule typically gives much larger values than are appropriate for a normal distribution.
2. Chebyshev's Rule does not apply to the normal distribution. 3. Chebyshev's Rule is not used because the histogram is well approximated by a normal curve. 4. Chebyshev's Rule does not apply to values in these ranges. 5. Chebyshev's Rule is the best way to solve this problem. (Ch.4, Q.9) need answers:
A sample of concrete specimens of a certain type is selected, and the compressive strength of each specimen is determined. The mean and standard deviation are calculated as x = 7000 and s = 300, and the sample histogram is found to be well approximated by a normal curve. (a)Approximately what percentage of the sample observations are between 6700 and 7300? (Round the answer to the nearest whole number.) Approximately %
(b) Approximately what percentage of sample observations are outside the interval from 6400 to 7600? (Round the answer to the nearest whole number.) Approximately %
(c) What can be said about the approximate percentage of observations between 6400 and 6700? (Round the answer to the nearest whole number.) Approximately %
(d) Why would you not use Chebyshev's Rule to answer the questions posed in parts (a)-(c)? 1. Chebyshev's Rule typically gives much larger values than are appropriate for a normal distribution.
2. Chebyshev's Rule does not apply to the normal distribution. 3. Chebyshev's Rule is not used because the histogram is well approximated by a normal curve. 4. Chebyshev's Rule does not apply to values in these ranges. 5. Chebyshev's Rule is the best way to solve this problem.
A sample of concrete specimens of a certain type is selected, and the compressive strength of each specimen is determined. The mean and standard deviation are calculated as x = 7000 and s = 300, and the sample histogram is found to be well approximated by a normal curve. (a)Approximately what percentage of the sample observations are between 6700 and 7300? (Round the answer to the nearest whole number.) Approximately %
(b) Approximately what percentage of sample observations are outside the interval from 6400 to 7600? (Round the answer to the nearest whole number.) Approximately %
(c) What can be said about the approximate percentage of observations between 6400 and 6700? (Round the answer to the nearest whole number.) Approximately %
(d) Why would you not use Chebyshev's Rule to answer the questions posed in parts (a)-(c)? 1. Chebyshev's Rule typically gives much larger values than are appropriate for a normal distribution.
2. Chebyshev's Rule does not apply to the normal distribution. 3. Chebyshev's Rule is not used because the histogram is well approximated by a normal curve. 4. Chebyshev's Rule does not apply to values in these ranges. 5. Chebyshev's Rule is the best way to solve this problem. A sample of concrete specimens of a certain type is selected, and the compressive strength of each specimen is determined. The mean and standard deviation are calculated as x = 7000 and s = 300, and the sample histogram is found to be well approximated by a normal curve. (a)Approximately what percentage of the sample observations are between 6700 and 7300? (Round the answer to the nearest whole number.) Approximately %
(b) Approximately what percentage of sample observations are outside the interval from 6400 to 7600? (Round the answer to the nearest whole number.) Approximately %
(c) What can be said about the approximate percentage of observations between 6400 and 6700? (Round the answer to the nearest whole number.) Approximately %
(d) Why would you not use Chebyshev's Rule to answer the questions posed in parts (a)-(c)? 1. Chebyshev's Rule typically gives much larger values than are appropriate for a normal distribution.
2. Chebyshev's Rule does not apply to the normal distribution. 3. Chebyshev's Rule is not used because the histogram is well approximated by a normal curve. 4. Chebyshev's Rule does not apply to values in these ranges. 5. Chebyshev's Rule is the best way to solve this problem.
Explanation / Answer
here it is given normal distribution with mean=7000 and sd=300
a. P(6700<x<7300)=P(6700-7000/300<z<7300-7000/300)=P(-1<z<1)=0.6827
b. P(6400<x<7600)=P(-2<z<2)=0.9545
c. P(6400<x<6700)=P(-2<z<-1)=0.1359
d.n practical usage, in contrast to the 68–95–99.7 rule, which applies to normal distributions, under Chebyshev's inequality a minimum of just 75% of values must lie within two standard deviations of the mean and 89% within three standard deviations. so answer is 2. Chebyshev's rule does not apply to normal diatribution
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