One or two tailed test?

[TomA]

Hi, I am currently struggling to decide whether the following problem requires a one or two tailed t test for a hypothesis test. I have uploaded a photo of the data used if needed.

'Test the individual significance of the explanatory variable. You should decide on an appropriate t-test (one tailed or two tailed) and explain why you've chosen this test.

Thanks in advance .

 

[hlsmith]

The selection of 1- or 2-tailed is based on the a priori stated hypothesis be tested. What is the hypothesis? Write it out and it should tell you what to do.