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# Help! Statistics rounding! watch

1. I really don't understand when you use rounded values or not in calculations in statistics.

I thought it was that you don't round anything but the final answer but I did a question just now where in the normal distribution, the standardised score: z value, was 1.497. So I found the probability with that but in the mark scheme, they rounded to 1.50 then continued.

Because if that my answer was one number off!! And I double checked m calculations. It was all right.

2. (Original post by pibobelebeep)
I really don't understand when you use rounded values or not in calculations in statistics.

I thought it was that you don't round anything but the final answer but I did a question just now where in the normal distribution, the standardised score: z value, was 1.497. So I found the probability with that but in the mark scheme, they rounded to 1.50 then continued.

Because if that my answer was one number off!! And I double checked m calculations. It was all right.

In the case where the table provided (not sure if these are provided in the new spec), the z values come in 2 d.p. so you always rounded to 2 d.p.

Not sure if this advice holds in the new spec.

Exceptions weren't values of z like 0.005 etc which are in a second, smaller table.
3. (Original post by Kevin De Bruyne)
In the case where the table provided (not sure if these are provided in the new spec), the z values come in 2 d.p. so you always rounded to 2 d.p.

Not sure if this advice holds in the new spec.

Exceptions weren't values of z like 0.005 etc which are in a second, smaller table.
Thanks a bunch!

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Updated: February 28, 2018
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