A research team investigates the potential association between hours of work and blood pressure. They want to see whether there is a statistically significant difference in blood pressure (SBP) before and after someone switches to a heavier-load job (from 40 hours per week to 55 hours or more). If they were to use the hypothesis testing procedure for this research question, what would be the appropriate test statistic to use?

1. One-sample t test

2. Matched-sample t test

3. One-sample proportion test

4. Independent-samples t test

2. Matched-sample t test

Step-by-step explanation:

The matched sample t test (or matched sample t test) is used when sample units from two data sets can be presented in form of pairs. Eg - Same people given a treatment, their before & after versions illustrate paired data sets. The test is used to check whether the two sets of paired data, have statistically significant different means.

Letting new variable 'd' as the difference between the two paired data series, x1 & x2. So, d = x1 - x2. 't' is calculated as undermentioned : -

t = (d - M) / [ sd / sqrt (n) ];

where M = assumed difference {here it is difference in blood pressure before & after job, i. e 55 - 40 = 15}