Hi Smriti,

t-tests can be used to determine if the means of two data sets are significantly different from each other, and are applied when data follows a normal distribution. The quantity of data tested is a irrelevant question. Now, the important answer is 1) what kind of antibacterial data is the input of your statistical model, or 2) how was your acquisition design (test for 1 or more factors, 1 or more groups).

Those questions will help you in choose one statistical test or another one to examine your data.

Anyway, i have found a nice reference about this: http://www.socialresearchmethods.net/kb/stat_t.php

Regards,

MM

Hi Smriti,

You will see different type of t-test is very easily explained and demonstrated using excel in this website, if you  still need it:

http://www.real-statistics.com/students-t-distribution/

Hi smirti, 

You can use to see the significant difference of mean between two groups. If sample size is less than 30 and normally distributed, then t test is better option.

You can use varrious pakages such as minitab, R  and SPSS etc