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Hi, Members
I got this question in interview.
Manager looks at the mean height which is recorded in the Database by summing all recorded heights and dividing by the number of recordings. He is surprised to see that the mean height is 3.15 and the maximum is 305. What has not he taken into account about how the data is being recorded?
Can anyone guide me, what could be answer or any suggestions ??
Thanks.
Calculation example:
(3000 * 3.0 + 1 * 305.0) / (3000 + 1) = 3.15092454
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Hi Raj-6888,
Agree with Olaf and Tom.
If you found the post which was helpful to your issue, you could kindly accept it as answer.
If you have any other question about SQL Server, please feel free to ask.
Best Regards,
Amelia
What has not he taken into account about how the data is being recorded?
That's more a mathematic / statistic question then a SQL Server one.
Answer: He missed the mean deviation. The max figure of 305 may exists one time, figure 3 may be 1000 times.
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I agree with Olaf,
I don't understand the question "how the data is being recorded?". The data is the data.
IMHO, the ANALYSIS of the data could be flawed. The other option is to throw out the high/low out of range values. But again, that is an analysis question, not a reason to change the "data being recorded".
Unless they are looking for an answer like "the table should have a date of measurement" or something. But that doesn't affect the query, because they didn't indicated a date range.