# [JMP] Does any body can explain me on one sample size what formula used in JMP?

#### yguns9

##### New Member
Hi, sir.

As below table, I have so many items to do analysis with One, Two, K sample mean.

Is there any jmp formula in "Sample size N" same as jmp under DOE "Sample size and power"

Item Sigma σ Delta δ Sample size N Method

A 1.0088 1.64 One sample mean

B 0.5747 1.31 One sample mean

C 0.9411 1.37 Two sample mean

D 0.5445 1.19 k sample mean

...

...

...

ZZZ

More information, I try calculating sample size by formula based on above table compared with using JMP under DOE "Sample size and power".

Result is different between applying formula in JMP table and DOE "Sample size and power"

Formula & result are as below.
Ceiling((Probit(1 - :Alpha / 2) + Probit(1 - :Beta)) ^ 2 / (Delta δ / Sigma σ) ^ 2)

Item Sigma σ Delta δ Sample size N Method

A 1.0088 1.64 4 One sample mean

but DOE result is

Sample Size
Testing if one mean is different from the hypothesized value.

Alph 0.05
Std Dev 1.0088
Extra Parameters 0
Supply two values to determine the third.
Enter one value to see a plot of the other two.

Difference to detect 1.64
Sample Size 7
Power 0.9

Does any body can explain me why I face different result?