You are going to test a hypothesis concerning the difference between two population means

1. You are going to test a hypothesis concerning the difference between two population means.  One of the steps to do this is to find the standard error.  Suppose you have two samples with 50 observations each and standard deviations of 77 and 67.1.  What is the standard error?  Answer to two decimal places.

2. You are going to test a hypothesis concerning two means where the null hypothesis involves a difference of 0.  Suppose that your two sample means are 25.4 and 31.7 while the estimated standard error is 8.1.  What is the test statistic?  Answer to two decimal places.

3. You are going to test a hypothesis concerning two means where the null hypothesis involves a difference of 0.  Suppose that your two sample means are 58.8 and 47.6 while the estimated standard error is 8.4.  What is the test statistic?  Answer to two decimal places.