Does the job satisfaction of assembly workers differ when their work is machine$-$paced rather than self$-$paced? Assign workers either to an assembly line moving at a fixed pace or to a self$-$paced setting. All subjects work in both settings, in random order. This is a matched pairs design. After two weeks in each work setting, the workers take a test of job satisfaction. The response variable is the difference in satisfaction scores, self$-$paced minus machine$-$paced.

The parameter of interest is the mean of the differences in scores in the population of all assembly workers.

Question $1$

List the Null hypothesis and alternative hypothesis to test if the job satisfaction of assembly workers differ when their work is machine$-$paced rather than self$-$paced.