Question

If you dont have a table of critical values, how can you calculate the critical value from the confidence level

Answer 1

If we do not have table for critical value table then we can use excel formula for Normal distribution, T distribution, And Chi square distribution.

For example if the distribution is normal and the confidence level is given then using excel formula which is =NORM.S.INV(CONFIDENCE LEVEL) , is used to find for a right tailed test, if for left tailed test the Formula used is =NORM.S.INV(1-CONFIDENCE LEVEL) and if it is for two tailed test then the formula used is =NORM.S.INV(CONFIDENCE LEVEL+1/2*(1-CONFIDNECE LEVEL))

Note the confidence level used here is nor the percentage value but the proportion value.