Aircraft Cable

See More About:    Relief Valve        Clear Plexiglas        How To Apply Woodturning Tools        

Thanks for visiting Woodturning Tools. You could soon be saving a lot of money and even time using our website Woodturning Tools. Do your search here for Aircraft Cable and act wisely to reap the benefits. Thanks for Visiting

Frequently Asked Questions...

I'm having trouble with this problem. Can anyone help solve.?

A random sample of 40 rolls of 5/16 inch diameter aircraft cable was taken from the recent production of the Calamity Cable Company. A piece was selected from each roll and fastened into a mechanical stretcher which could read the force which broke the cable. The mean of the 40 samples was 517 pounds with a sample standard deviation of 44 pounds. What is the 99% confidence level of the true mean, m, of the breaking strength of that kind of CCC's cable?

possible solutions from book.....

a. 510 < m < 524

b. 506 < m < 528

c. 501 < m < 533

d. 499 < m < 535

e. 497 < m < 537

f. none of these


Best Answer...

Answer:

Since we do not know the population standard deviation, we will have to use the T interval.
After reading the problem, we know that...
- x-bar (the sample mean)=517
- s (sample standard deviation)=44
- n (the same size)=40
- Confidence level is 99% or 0.99
If you have a TI-83/84 plus calculator then go to...
STAT-TETS-8:TInterval
Inpt: Stats
x-bar: 517
Sx: 44
n: 40
C-Level: 0.99
and press "calculate"
So the interval is (498.16, 535.84). I think the solution is d.