What and Before conducting any statistical tests, the researcher checks the normality of the distribution of blood pressure changes in both groups and finds that they approximately follow a normal distribution. Based on this information, propose a suitable statistical test to compare the mean changes in blood pressure between the two groups. Describe the steps involved in conducting this test, including how to set up the null and alternative hypotheses, the type of test statistic to use, how to calculate the degrees of freedom, and how to interpret the p$-$value. Additionally, explain what would constitute a statistically significant result and discuss the potential implications of type I and type II errors in the context of this study.