Answer:
34
Step-by-step explanation:
180 since it is supplementary
then minus 100 which is 80 then minus 12 which is 68 then half that which is 34
Answer:


Step-by-step explanation:
Given



Required
Find P(A) and P(B)
We have that:
--- (1)
and
--- (2)
The equations become:
--- (1)

Collect like terms


Make P(A) the subject

--- (2)


Substitute: 
![[0.770 - P(B)] * P(B) = 0.144](https://tex.z-dn.net/?f=%5B0.770%20-%20P%28B%29%5D%20%2A%20P%28B%29%20%3D%200.144)
Open bracket

Represent P(B) with x

Rewrite as:

Expand

Factorize:
![x[x - 0.45] - 0.32[x - 0.45]= 0](https://tex.z-dn.net/?f=x%5Bx%20-%200.45%5D%20-%200.32%5Bx%20-%200.45%5D%3D%200)
Factor out x - 0.45
![[x - 0.32][x - 0.45]= 0](https://tex.z-dn.net/?f=%5Bx%20-%200.32%5D%5Bx%20-%200.45%5D%3D%200)
Split

Solve for x

Recall that:

So, we have:

Recall that:

So, we have:


Since:

Then:


Answer:
A
Step-by-step explanation:
The z score for a confidence level of 99% is 2.575.. You need to know this to complete this type of problem.. the other two commonly used confidence levels are 90% and 95% having z scores of 1.645 and 1.96 respectively. You need to memorize this!
To find the confidence interval, it will be defined as the sample mean plus/minus the margin of error.. Now to find the margin of error, divide the standard deviation of 12 by the square root of the number of elements in your sample(√250). Then take that result and multiply it by the Z score I mentioned above for a 99% confidence level.
In this case: the sample mean is 70 and the margin of error is approximately 1.95
So to calculate the confidence interval, do the following:
70 - 1.95 = 68.05 rounded to the nearest whole number is 68
70 + 1.95 = 71.95 rounded to the nearest whole number is 72
Looks like that would be the last choice. hope this helps.. it's been awhile since my work with statistics :-)
The answer is 6 centimeters