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 - 3000 and s = 300, and the sample histogram is found to be well approximated by
a normal curve.
(ə)Approximately what percentage of the sample observations are between 2700 and 3300? (Round the answer to the
nearest whole number
Approximately.
Enter an exact number
(6) Approximately what percentage of sample observations are outside the interval from 2400 to 3600? (Round the answer to
the nearest whole number.)
Approximately
%
96
(c) What can be said about the approximate percentage of observations between 2400 and 2700? (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)?
Chebyshev's Rule is the best way to solve this problem.
Chebyshev's Rule does not apply to values in these ranges.
Chebyshev's Rule is not used because the histogram is well approximated by a normal curve.
Chebyshev's Rule does not apply to the normal distribution.
Chebyshev's Rule typically gives much larger values than are appropriate for a normal distribution