2(4z-9-11)=166-46
8z-18-22=120
8z-40=120
Add 40 from both side
8z-40+40=120+40
8z=160
Divided 8 from both side
8z/8=160/8
z=20. Hope it help!
Answer:
2
Step-by-step explanation:
2^2+4(2)=12
4+8=12
So, x=2
Hope this helps.
-Amelia
Answer:
V = 672; SA = 544; LA = 448
Step-by-step explanation:
Answer:
The 90% confidence interval for the mean time required by all college graduates is between 5.36 years and 5.44 years.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so
Now, find the margin of error M as such
In which
is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 5.4 - 0.04 = 5.36 years.
The upper end of the interval is the sample mean added to M. So it is 5.4 + 0.04 = 5.44 years.
The 90% confidence interval for the mean time required by all college graduates is between 5.36 years and 5.44 years.