Answer:
1. (-125 a - 5.75) x + b c (605 x - 550 x^2) + 10.75
2. -125 a x + x (-550 b c x + 605 b c - 5.75) + 10.75
3. 0.25 (-500 a x - 220 b c (10 x - 11) x - 23 x + 43)
Step-by-step explanation:
I think you could times 4 and 5 to get 20
<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
The answer is $8.43 for this question