Question #3727

Do a two sample t test. Assume that this is a two sided test with alpha 5%. <br>Find the test stat, p-value and make a decision about the null.

Expert's answer

Null hypothesis is that the difference between the two groups is 0.

Alternative hypothesis - the difference between two means is not zero.

Test statistics can be found by the formula

where x_{1}, x_{2} - are the means of two samples, SD_{1,2} - standard deviations , n_{1,2 }- the number of observations of two samples respectively.

Then you have to calculate the number of degrees of freedom:

and find p-value from the tables (or using t to p value calculator).

If p-value is more than 0.1 (performing two-sided test you must use doubled alpha), we do not reject the null hypothesis; otherwise - we reject it.

Alternative hypothesis - the difference between two means is not zero.

Test statistics can be found by the formula

where x

Then you have to calculate the number of degrees of freedom:

and find p-value from the tables (or using t to p value calculator).

If p-value is more than 0.1 (performing two-sided test you must use doubled alpha), we do not reject the null hypothesis; otherwise - we reject it.

## Comments

## Leave a comment