Answer:
a
The estimate is 
b
Method B this is because the faulty breaks are less
Step-by-step explanation:
The number of microchips broken in method A is 
The number of faulty breaks of method A is 
The number of microchips broken in method B is 
The number of faulty breaks of method A is 
The proportion of the faulty breaks to the total breaks in method A is


The proportion of the faulty to the total breaks in method B is

For this estimation the standard error is

substituting values


The z-values of confidence coefficient of 0.95 from the z-table is

The difference between proportions of improperly broken microchips for the two breaking methods is mathematically represented as
![K = [p_1 - p_2 ] \pm z_{0.95} * SE](https://tex.z-dn.net/?f=K%20%3D%20%5Bp_1%20-%20p_2%20%5D%20%5Cpm%20z_%7B0.95%7D%20%2A%20SE)
substituting values
![K = [0.08 - 0.07 ] \pm 1.96 *0.0186](https://tex.z-dn.net/?f=K%20%3D%20%5B0.08%20-%200.07%20%5D%20%5Cpm%201.96%20%2A0.0186)

The interval of the difference between proportions of improperly broken microchips for the two breaking methods is

Answer:
a) 0.9
b) Mean = 1.58
Standard Deviation = 0.89
Step-by-step explanation:
We are given the following in the question:
A marketing firm is considering making up to three new hires.
Let X be the variable describing the number of hiring in the company.
Thus, x can take values 0,1 ,2 and 3.

a) P(firm will make at least one hire)

Also,


b) expected value and the standard deviation of the number of hires.
![E(x^2) = \displaystyle\sum x_i^2P(x_i)\\=0(0.1) + 1(0.4) + 4(0.32) +9(0.18) = 3.3\\V(x) = E(x^2)-[E(x)]^2 = 3.3-(1.58)^2 = 0.80\\\text{Standard Deviation} = \sqrt{V(x)} = \sqrt{0.8036} = 0.89](https://tex.z-dn.net/?f=E%28x%5E2%29%20%3D%20%5Cdisplaystyle%5Csum%20x_i%5E2P%28x_i%29%5C%5C%3D0%280.1%29%20%2B%201%280.4%29%20%2B%204%280.32%29%20%2B9%280.18%29%20%3D%203.3%5C%5CV%28x%29%20%3D%20E%28x%5E2%29-%5BE%28x%29%5D%5E2%20%3D%203.3-%281.58%29%5E2%20%3D%200.80%5C%5C%5Ctext%7BStandard%20Deviation%7D%20%3D%20%5Csqrt%7BV%28x%29%7D%20%3D%20%5Csqrt%7B0.8036%7D%20%3D%200.89)
A
100+89.50×36
=3,322
b
3,322−2,900
=422
c
2,900÷89.50
=33
18 is 90% of 20
That is the correct answer :)
186-42 = 144
Original price is 288 (5th option)
Equation is 0.5x + 42 = 186 (last option)
Please give brainliest I’d really appreciate it.