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Post Number: 105
Posted on Sunday, 22 May, 2011 - 06:55 am:   

I need a clarification before my S2 exam on Thursday. How do I find a value of P(Z<0.7925)? This is bearing mind that all the table values are to 2 decimal places. Previously, I have compare it to the closest value and then subtract to get my final result. For example, if I need P(Z<1.212), I would compare it to P(Z<1.21) and P(Z<1.22). Since it is closer to 1.21, I would subtract .002 from the table value. Is this method correct? I am getting a slightly different result to the questions. Please help.

Veteran poster

Post Number: 644
Posted on Sunday, 22 May, 2011 - 11:18 am:   

"For the purposes of the examination it is sufficient to round your value to two decimal places and read directly from the tables and thus avoid having to interpolate." That's a direct quote from an old S1 textbook, so should be good advice.

Frequent poster

Post Number: 106
Posted on Monday, 23 May, 2011 - 04:14 am:   

Thanks. Much appreciated.

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