Here are the answers:
1.) DC=D’C’
2.) 3.) ED=E’D’
The best answer here would be choice B
Answer: 86.64%
Step-by-step explanation:
Let x be a random variable that represents the diameter of metal samples.
Given : Population mean : 
Standard deviation: 
Specified tolerance on the diameter is 0.75 mm.
i.e. range of diameter = 10-0.75< x <10+0.75 = 9.25< x< 10.75
Formula to find the z-score corresponds to x: 
At x= 0.75, 

Using standard normal table for z-value,
P-value : 
∴ Percentage of samples manufactured using this process satisfy the tolerance specification = 86.64%