<h2>
Answer with explanation:</h2>
The confidence interval for population mean is given by :-
(1)
, where
= sample mean
z* = critical value.
SE = standard error
and
,
= population standard deviation.
n= sample size.
As per given , we have


n= 15
It is known that ring diameter is normally distributed.
By z-table ,
The critical value for 95% confidence = z*= 1.96
A 99% two-sided confidence interval on the true mean piston diameter :
(using (1))

[Rounded to three decimal places]
∴ A 99% two-sided confidence interval on the true mean piston diameter = (74.020, 74.022)
By z-table ,
The critical value for 95% confidence = z*= 1.96
A 95% lower confidence bound on the true mean piston diameter:
(using (1))
[Rounded to three decimal places]
∴ A 95% lower confidence bound on the true mean piston diameter= 74.020
Answer: 
Step-by-step explanation:
We have the following polynomial:

This is a polynomial of the form
. Following this rule to expand it, we have:


Applying common factor
:

Note the polynomial inside the parenthesis is a perfect square trinomial, which can be factored to
. Hence, the final simplification is:

6/24* 100= 25%. You multiply top ( 6 and 100) and divide to bottom (600 and 24) to get 25%.
Answer:
±sqrt( H *f•c)= L
Step-by-step explanation:
H=L^2/f•c
Multiply each side by fc
H *fc=L^2/f•c * fc
H *f•c=L^2
Take the square root of each side
±sqrt( H *f•c)= sqrt(L^2)
±sqrt( H *f•c)= L