Simple just do normal simple algebra:)
Answer:
The 95% confidence interval for the average number of years until the first major repair is (3.1, 3.5).
Step-by-step explanation:
The (1 - <em>α</em>)% confidence interval for the average using the finite correction factor is:

The information provided is:

The critical value of <em>z</em> for 95% confidence level is,
<em>z</em> = 1.96
Compute the 95% confidence interval for the average number of years until the first major repair as follows:


Thus, the 95% confidence interval for the average number of years until the first major repair is (3.1, 3.5).
Answer:
B. Parallel
Step-by-step explanation:
Equation 1 simplified: y = 3x+7
Equation 2 simplified: y = -x/3-3
The slopes are completely different, ruling out the possibility of the lines being parallel.
But we also see the slopes of the equations are opposite and negative to each other. Making the lines perpendicular.