Interpreting p value in SciPy Welch's T-Test

Question

Can someone help me understand the meaning of the p-value of the Whelch's T Test in SciPy?

test = stats.ttest_ind(x, y, equal_var=False)

gives me

Ttest_indResult(statistic=5.4320992218489925, pvalue=7.614106565771353e-08)

But with a statistic of 5.43, shouldn't be a 0.00000... p-value according to the T table instead?

RLave · Accepted Answer · 2018-07-13T08:29:37.097

2

It is in fact a pvalue of 0.000000...

That format tells you that the value is 7.614106565771353 times 10^-8, So it's 0 point followed by 7 zeros than 7614 ecc..

edited Jul 13 '18 at 08:29

answered Jul 13 '18 at 08:22

RLave

thanks! That makes perfect sense, i didn't think about it. – Marco Goldin Jul 13 '18 at 08:27
1

It is 0 point followed by **seven** zeros and then 7614... Just like $10^{-3}$ is 0,001 – Łukasz Deryło Jul 13 '18 at 08:28

1 Answers1