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:

Answer: absolute value
Step-by-step explanation:
Sorry for my writing it’s horrible ik I’m in a hurry rn lol
9514 1404 393
Answer:
30°, 150°
Step-by-step explanation:
You know the answer to this because you have memorized the short table of trig function values.
sin(θ) = 1/2 for θ = 30° and θ = 150°
2.5y + 3x = 27
5x - 2.5y = 5
Align the variables to make solving this easier.
2.5y + 3x = 27
-2.5y + 5x = 5
You can see that the 2.5y and -2.5y cancel each other out. Then add the 3x and 5x, and 27 + 5.
3x = 27
5x = 5
8x = 32
Divide both sides by 8.
x = 4
Now input that x into one of the equations to get y.
2.5y + 3(4) = 27
2.5y + 12 = 27
2.5y = 15
y = 6
The answer to this system of equations is x = 4, y = 6. (4, 6)