what quartile 1 and quartile 3? And how to t-test?

2 answers

Easiest way to learn is search wikipedia quartile and t-test
Quartile 1 is the 25th percentile (25% of the scores are lower), while the quartile 3 is the 75th percentile. Quartile 2 is the median.

I searched Google under the key words "t-test" to get these possible sources:

http://en.wikipedia.org/wiki/Student's_t-test
http://www.socialresearchmethods.net/kb/stat_t.php
http://ccnmtl.columbia.edu/projects/qmss/t_about.html
http://web.uccs.edu/lbecker/SPSS/ttest.htm

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.

I hope this helps a little more. Thanks for asking.