<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
Ur answer is going to be 49
Answer:
<h2>How many car accidents involve airbag malfunctions?</h2><h2 />
This is because there's no need to survey an entire population for accurate results.
The other 3, regarding Colorado residents, middle school students, and classmates are considered a population.
For testing the amount of car accidents, a population is not needed.
<em />
<em>I hope this helped you!</em>
Answer:
Step-by-step explanation:
quadratic equation: ax² + bx + c =0
x' = [-b+√(b²-4ac)]/2a and x" = [-b-√(b²-4ac)]/2a
6 = x² – 10x ; x² - 10x -6 =0
(a=1, b= - 10 and c = - 6
x' = [10+√(10²+4(1)(-6)]/2(1) and x" = [10-√(10²+4(1)(-6)]/2(1)
x' =5+√31 and x' = 5-√31