2/21 * 7/8
14/168
divide top and bottom by 14
1/12
Answer:

Step-by-step explanation:
The firm tests 75 parts, and finds that 0.25 of them are notusable
n = 75
x = 0.25 \times 75 = 18.75≈19



Confidence level = 95%
So, Z_\alpha at 95% = 1.96
Formula of confidence interval of one sample proportion:


Confidence interval 
Answer:
Slope = -2
Y intercept = 4
Equation. y = -2x +5
Step-by-step explanation:
Using points, (1,2) and (3,-2)
Slope = (-2-2)/(3-1) = -4/2 = -2
Y intercept = 4
-2 = (y-3)/(x-1)
-2(x-1) = y-3
-2x +2 = y-3
y = -2x +2 +3
y = -2x +5
The answer is D I think. I'm not really good with math oof