Answer:
a
The 95% confidence interval is 
b
The sample proportion is 
c
The critical value is 
d
The standard error is 
Step-by-step explanation:
From the question we are told that
The sample size is n = 200
The number of defective is k = 18
The null hypothesis is 
The alternative hypothesis is 
Generally the sample proportion is mathematically evaluated as

Given that the confidence level is 95% then the level of significance is mathematically evaluated as



Next we obtain the critical value of
from the normal distribution table, the value is

Generally the standard of error is mathematically represented as

substituting values


The margin of error is

=> 
=> 
The 95% confidence interval is mathematically represented as

=> 
=> 
Answer:
A: C = 2: 1
Step-by-step explanation:
Please see the attached pictures for the full solution.
Further explanantion (2nd image):
The reason why the ratio of A: C is equal to the ratio if 2A: 2C is that the number of parts of A and C is equal, which is 2 parts. If I were to divide both 2A and 2C by 2 to find the ratio of A: C, I would obtain 15: 15/2. However, ratios are expressed as whole numbers and thus, we would multiply the whole ratio by 2 again and the answer would still be 30: 15. This ratio is not in the simplest form since both can be divided by 15. Thus, dividing both sides of the ratio by 15 will leave us with the final answer of
A: C= 2: 1.
☆ An alternative method is to simplify the ratio 3B: 2C at the beginning.
3B: 2C
= 36: 15
= 12: 5
Multiply the first ratio by 2 so 3B has 12 parts in both ratios:
2A: 3B
= 10: 12
Combining the 2 ratios together,
2A: 3B: 2C
= 10: 6: 5
2A: 2C
= 10: 5
= 2: 1
A: C= 2: 1
The sound intensity of the Pile Driver is 39.5
or nearly 40 times the sound intensity of the jackhammer.
Given with Loudness in dB for pile driver = 112 dB
We have to convert it in terms of sound intensity.
First,
112dB/10 = 11.2
Then we'll use this as exponent of 10
(10)^(11.2) = 1.5849 * 10 ^ 11
Then use the equation of Watts per square meter to find the intensity:
I / (10^-12 W/m^2) =1.5849 * 10 ^ 11
I = sound intensity = 0.158
Then compare:
Sound intensity of Pile Driver/ Sound intensity of Jackhammer
(0.158) / (0.004)
= 39.5
or nearly 40 times the jackhammer.