Final answer:
Given a test statistic of 1.9 and a p-value of 0.029 against a significance level of 0.03, you should reject the null hypothesis as the p-value is less than the significance level.
Step-by-step explanation:
In hypothesis testing, we compare the p-value to our predetermined level of significance, denoted as α (alpha), to decide whether to reject the null hypothesis. Given a test statistic of 1.9 with a sample size of 21, you have calculated a p-value of 0.029. Considering your significance level is 0.03, the p-value is less than α (0.029 < 0.03), hence you should reject the null hypothesis.
To define what type of test you are performing (one-tailed or two-tailed), you would need additional information about the direction of the alternative hypothesis. However, as the p-value is lower than the significance level, the decision to reject or fail to reject the null hypothesis is not dependent on it being a one-tailed or two-tailed test. The decision-making process is the same; if the p-value is less than α, we reject the null hypothesis.