Answer:
And we are 95% confident that the true mean of chloride concentration is between 0.375 and 0.377 cc/ cubic meter
Step-by-step explanation:
Data provided
represent the sample mean for the chloride concentration
population mean (variable of interest)
s=0.0012 represent the sample standard deviation
n=15 represent the sample size
Confidence interval
The confidence interval for the mean is given by the following formula:
(1)
Since we need to find the critical value first we need to begin finding the degreed of freedom
The Confidence is 0.95 or 95%, the significance would be
and
, and the critical value for this case with a t distribution with 14 degrees of freedom is
And the confidence interval is:
And we are 95% confident that the true mean of chloride concentration is between 0.375 and 0.377 cc/ cubic meter
The smaller sector is 360-255=105 degree
it is 105/360 portion of the whole circle, and the area of the whole circle is πr², r is 14
so the area of the smaller sector is (105/360)*π*14²
run those numbers through your calculator, use 3.14 for π, you get 179.5
if you are looking for area of the larger sector, it would be
(255/360)*π*14²=435.94
First answer haha~ I think I answered all your questions so far ;)