Help with t-test. Accecpting or rejecting null hypothesis?

Question

Ok so I have data from 2 samples one is a control and the other is with an added chemical.  The data shows the strengths for a compound with or without this chemical added.

Test 1 (without):  25.1, 24.4, 25.8, 25.2, 23.9, 24.7, 24.3, 26.0, 23.8, 24.6
Test 2 (with):  25.3, 26.8, 26.5, 24.5, 27.2, 24.8, 24.1, 25.9, 25.3

from my calculations i got:

degree of freedom = 18,  pooled varience = 0.80335, standard error of difference = 0.4008

t- value = 1.896,  critical value (0.05)  = 1.734

my question is do i accecpt or reject the null hypothesis.  For instance do I say "since the t value is close to the critical value, adding the chemical will increase the strength"

Thanks!

Anonymous · Accepted Answer

The critical value is your 'cut off' mark. Your t-value falls over that cut-off mark, so you must reject the null hypothesis in favour of the alternative hypothesis, and it appears that the strength of a compound with chemicals added is different to that with no chemicals.

royston · Answer

for 5% magnitude: >> i think of which you reject the null hypothesis whilst the generated p fee is decrease than 0.05, and you settle for the null hypothesis whilst the generated p fee is larger than 0.05? ultimate. For a one-tail chi-sq. try: If the calculated chi-sq. fee is larger than the intense fee, reject the null hypothesis. the two tests provide a similar result.

Trending News

Help with t-test. Accecpting or rejecting null hypothesis?

2 Answers