Question

A certain group of test subjects had pulse rates with a mean of 83.683.6 beats per minute and a standard deviation of 10.310.3 beats per minute. Use the range rule of thumb to identify the limits separating values that are significantly low or significantly high. Is a pulse rate of 134.2134.2 beats per minute significantly low or significantly​ high?(A) Significantly high comma because it is greater than two standard deviations above the mean.Significantly high, because it is greater than two standard deviations above the mean.(B) Significantly low comma because it is less than two standard deviations below the mean.Significantly low, because it is less than two standard deviations below the mean.(C) Neither comma because it is within two standard deviations of the mean.Neither, because it is within two standard deviations of the mean.(D) It is impossible to determine with the information given.

Answer 1

It is significantly high, because it is greater than two standard deviations above the mean.

Explanation:

Mean =
`\mu =83.6`

Standard deviation =
`\sigma =  10.3`

The range rule of thumb for 2 standard deviations :
`\mu - 2\sigma` to
`\mu+2\sigma`

Substitute the value for range

Range =
`83.6-2(10.3)` to
`83.6+2(10.3)`

Range =
`63` to
`104.2`

Now we are asked is a pulse rate of 134.2 beats per minute significantly low or significantly​ high .

Since 134.2 beats per minute does lie in the range

So, It is significantly high, because it is greater than two standard deviations above the mean.