Here are a few hints:
1. Try an independent groups t-test to calculate the t-test statistic.
2. Degrees of freedom for an independent groups t-test is this: n1 + n2 – 2
3. Compare your test statistic to the critical values listed. If the test statistic exceeds the critical values, reject the null and conclude a difference. If the test statistic does not exceed the critical values, do not reject the null (you cannot conclude a difference in this case). I hope this will get you started.