W=15
Subtract 80 from both sides then you divide by -2w.
Step-by-step explanation:
angle AOB = x+3
angle AOC = 2x + 11
angle BOC = 4x-7
angle AOC = angle AOB + angle BOC
=> 2x +11 = (x+3) + (4x-7)
2x +11 = 5x - 4
=> 3x = 15
x = 5
subst x = 5 in the given formulas
angle AOB = x +3 =8
angle AOC = 2x + 11 = 21
angle BOC = 4x - 7 = 13
Answer:
Margin of error of 0.0485 hours.
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 
.
That is z with a pvalue of 
, so Z = 1.96.
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.
In this question:
The margin of error is of:
Margin of error of 0.0485 hours.
I really don't know how toowrk it out on paper, I'm afraid. I just looked at it, and somehow knew that the answers are 7 and 9.
