Question

Please explain what type of test to perform a statistical significant difference of 0.05 and how to perform it on excel.

Treatment: Non-treated supernatant, n=2, but each sample is measured twice, so there are 4 concentrations: 16.425, 16.175, 18.325, 17.925

Treatment: Stressed supernatant, n=2, but each sample is measure twice, so there are 4 concentrations: 2.425, 2.925, 3.175, 2.355

Answer 1

Excel input:

Excel > Data > Data Analysis > t-Test Paired Two Sample for means

Excel output:

t-Test: Paired Two Sample for Means
	Non- treated supernatant	Stressed supernatant
Mean	17.2125	2.72
Variance	1.147291667	0.156433333
Observations	4	4
Pearson Correlation	0.209098275
Hypothesized Mean Difference	0
df	3
t Stat	27.30841301
P(T<=t) one-tail	5.38839E-05
t Critical one-tail	2.353363435
P(T<=t) two-tail	0.000107768
t Critical two-tail	3.182446305

Hypothesis:

H0 : µD = 0

Ha : µD not = 0 (Two tailed)

Test:

t stat = 27.3084

P value = 0.0001

P value < 0.05, Reject H0

Conclusion:

There is enough evidence to conclude that there is a statistical significant difference between Non-treated supernatant and Stressed supernatant at 5% significance level