Iwant to know which of two manufacturing methods will be better. i create 10 prototypes using the first process, and 10 using the second. there were 3 defectives in the first batch and 5 in the second. find a 95% confidence interval for the difference in the proportion of defectives.
a. (-0.62, 0.22)
b. (-0.56, 0.22)
c. (-0.493, 0.160)

Option A

Step-by-step explanation:

Given information:

Using the given information we get

The formula for confidence interval for the difference of proportions is

From the standard normal table the value of z* at 5% confidence interval is 1.96.

Substitute the given values in the above formula.

Therefore, the correct option is A.

2.2°  

step-by-step explanation:

let θ = the angle of elevation.

tanθ =77/2020

tanθ = 0.038 12

      θ = tan⁻¹0.038 12

      θ = 2.2°