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Question
Two workers on the same job show the following results:
| Worker P | Worker Q | |
| Mean time for completing the job (hours) | 33 | 21 |
| Standard Deviation (hours) | 9 | 7 |
Which worker seems to be faster in completing the job?
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Solution
| Worker P | Worker Q | |
| Mean time for completing the job (hours) | `bar"p"` = 33 | `bar"q"` = 21 |
| Standard Deviation (hours) | σp = 9 | σq = 7 |
C.V. (P) = `(sigma_"p")/bar"p"xx 100`
= `(9)/(33) xx 100`
= 27.27%
C.V. (Q) = `(sigma_"q")/(bar"q") xx 100`
= `7/21xx100`
= 33.33%
Since, `bar"p"` > `bar"q"`
i.e., expected time for completing the job is less for worker Q.
∴ Worker Q seems to be faster in completing the job.
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