ci_twosample_tnonpooled(A, B, cl)

Computes a confidence interval for the difference of two means. Arrays A and B store the samples and cl is the confidence level.
Assumes the samples are independent and that the populations are either normal or large.

See also ci_twosample_pro ci_twosample_tpaired ci_twosample_tpooled 

Example

(See NOTE below)

a=(370, 345, 360, 450, 510, 505, 445, 335, 295, 280, 315, 325, 490, 500)

( 370 345 360 450 510 505 445 335 295 280 315 325 490 500 )

b=(430, 455, 445, 490, 455, 535 )

( 430 455 445 490 455 535 )

ci_twosample_tnonpooled(a, b, .99)

Two-Sample Non Pooled-T Test.

Confidence interval for the difference of two means.

Confidence level : 0.99 (99%)

Results:

m1 : 394.64285714285717

m2 : 468.3333333333333

s1 : 84.74995542804105

s2 : 38.16630276391292

df  : 17

Interval  : (-153.3690172008206, 5.988064819868299 )

Margin of error : 79.67854101034445

NOTE: The data used in this example was taken from the textbook Introductory Statistics 6th Ed. by Neil A. Weiss with kind permission of Addison Wesly Longman, Inc. (AWL). AWL does not endorse nor it supports the Calcugator.