Answer:
b
Step-by-step explanation:
The 60$ system had a greater percentage decrease because it was a lower number to begin with. Taking the same portion out of two different numbers will always be a greater decrease for the lower number.
Answer:


And the margin of error with this one:


Step-by-step explanation:
Assuming that the parameter of interest is the sample mean
. And we can estimate this parameter with a confidence interval given by this formula:
(1)
For this case the confidence interval is given by (1.9, 3.3)
Since the confidence interval is symmetrical we can estimate the sample mean with this formula:


And the margin of error with this one:


The equations (-75)(-49)=3,675 the answer