Answer:
a) The confidence interval is 
.
Step-by-step explanation:
We have to calculate a confidence interval (CI) of a difference of proportions.
For the existing procedure, the proportion is:
For the new procedure, the proportion is:
To calculate the CI, we need to estimate the standard deviation
For a 90% CI, the z-value is 1.64.
Then, the CI is:
to do it in mental math: you can ignore the zeroes in 400 for now.
4*14 = 4*10 + 4*4 = 40 + 16 = 56
now add the zeroes back on: 5600m
Answer:
x - 2
Step-by-step explanation:
2x - 1 + 4x - 11
First, you want to combine like terms.
We can see that the one and eleven can go together, so add them together.
2x + 4x - 12
The reason that we made one, and eleven, negative twelve, is because they are both being subtracted from the numbers before that.
6x - 12
We added the 2x, and the 4x together to make 6x.
Another way to write this would be x - 2, because you can simplify it by dividing it by 6.
Answer:
z=-3
Step-by-step explanation:
-5z+9=24 so, subtract 9 from both sides becuase of liked terms to get -5z=15, then divide both sides by -5 to get z = -3 hope it helps:)
Answer:
x = 3
Step-by-step explanation:
Add 1 on both sides.
We get:
-2x = -6
Now divide -6 by -2...
-6/-2 = 3
