Answer:
we reject H₀
Step-by-step explanation: Se annex
The test is one tail-test (greater than)
Using α = 0,05 (critical value ) from z- table we get
z(c) = 1,64
And Test hypothesis is:
H₀ Null hypothesis μ = μ₀
Hₐ Alternate hypothesis μ > μ₀
Which we need to compare with z(s) = 2,19 (from problem statement)
The annex shows z(c), z(s), rejection and acceptance regions, and as we can see z(s) > z(c) and it is in the rejection region
So base on our drawing we will reject H₀
Y=3
..............................
First, subtract 63 from 75 to find out how much it decreased.
75 - 63 = 12
Divide 12 by 75.
12 / 75 = 0.16
In percents, that is 16%.
He spent 16% less this month.
Hope this helps!