K
kartik_newpro
Member
I have 2 queries regarding using interpolation to calculate chi-square probabilities. Assume chi-square = X for convenience
1. P(X4 > 1.064)
The chi-square percentage point tables directly shows this as 90%. But if I interpolate using the probability tables I get a different answer. Just tell me if interpolation is incorrect.
P(X < 1.0) = 0.0902 and P(X < 1.5) = 0.1734
0.0902 + (1.5 - 1.064)/(1.5 - 1.0) * (0.1734 - 0.0902) = 0.1628
P(X4 > 1.064) = 1 - 0.1628 = 0.8372 or 83.72%.
Where have I gone wrong?
2. P(X29 < 56.84)
From the tables, P(X > 52.34) = 0.05 and P(X > 58.30) = 0.01
Therefore,
0.01 + (58.30 - 56.84)/(58.30 - 52.34) * (0.05 - 0.01)
This doesnt give the right answer. What is the right way to interpolate?
Thanks
1. P(X4 > 1.064)
The chi-square percentage point tables directly shows this as 90%. But if I interpolate using the probability tables I get a different answer. Just tell me if interpolation is incorrect.
P(X < 1.0) = 0.0902 and P(X < 1.5) = 0.1734
0.0902 + (1.5 - 1.064)/(1.5 - 1.0) * (0.1734 - 0.0902) = 0.1628
P(X4 > 1.064) = 1 - 0.1628 = 0.8372 or 83.72%.
Where have I gone wrong?
2. P(X29 < 56.84)
From the tables, P(X > 52.34) = 0.05 and P(X > 58.30) = 0.01
Therefore,
0.01 + (58.30 - 56.84)/(58.30 - 52.34) * (0.05 - 0.01)
This doesnt give the right answer. What is the right way to interpolate?
Thanks