ht_twosample_std(A, B, alpha, type)

Hypothesis test for two population standard deviations. Arrays A and B store the samples. Parameter type can be 0 (left tail), 1 (right tail), or 2 (both tails).

See also ht_twosample_pro ht_twosample_tpaired ht_twosample_tpooled 

Example

(See NOTE below)

a=(2288, 2368, 2528, 2144, 2160, 2384, 2304, 2240, 2208, 2112 )

( 2288 2368 2528 2144 2160 2384 2304 2240 2208 2112 )

b=(2592, 2512, 2576, 2176, 2304, 2384, 2432, 2112, 2288, 2752)

( 2592 2512 2576 2176 2304 2384 2432 2112 2288 2752 )

ht_twosample_std(a,b,.05,2)

F Test for Two Sample Standard Deviations.

Hypothesis test for two independent samples.

Ho : s1==s2 

Ha : s1!=s2

Significance level : 0.05 (5.0%)

Results:

s1 : 128.32181766515345

s2 : 199.66905952934553

Test statistics F : 0.41302796803652964

Critical value left found is 0.24838583518527774

Critical right value found is 4.025994158225101

P value : 0.20389131929301718

Do not reject the null hypothesis.

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.