Answer:
controlled experiment
Step-by-step explanation:
Controlled experiment is a type of experiment in which except for only one variable, everything is kept constant.
The common type of the controlled experiment compares the control group against the experimental group. All the variables are identical between two groups except factor which is being tested.
Big advantage of the controlled experiment is that one can eliminate much of uncertainty about the results.
I thinks it’s -x-4 I’m not sure
Answer:

And for this case we want to test the following hypothesis:
Null hypothesis: 
Alternative hypothesis: 
For this case since the lower value of the confidence interval is higher than 42000 we have enough evidence to reject the null hypothesis at the 55 of significance and we can conclude that the true mean is significantly different from 42000
Step-by-step explanation:
The confidence interval for the mean is given by the following formula:
(1)
And for this case the 95% confidence interval is already calculated as:

And for this case we want to test the following hypothesis:
Null hypothesis: 
Alternative hypothesis: 
For this case since the lower value of the confidence interval is higher than 42000 we have enough evidence to reject the null hypothesis at the 55 of significance and we can conclude that the true mean is significantly different from 42000
Given equation of the line ,
Simplify ,

Transpose terms to RHS ,
Divide both sides by 5 ,
Now we know the slope intercept form of the line as
we have ,
As we know that the slope of all parallel lines are same . Henceforth ,