For a confidence level of 98% with a sample size of 18, find the critical t value.

Answer 1

Hi Amy,

Look up a t-table online. The first one you see will be from San Jose State--this is a nice, comprehensive one. Sorry I cannot link here as Wyzant reviews posts when I link. Your test is two-sided, confidence levels are at the bottom of the table, so look for 98% there. Degrees of freedom is sample size minus 1, so:

df=18-1=17

In rows, look for 17 degrees of freedom. Result is:

t_.98,17=2.567

I hope this helps.