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
A point (-0.8, 0.6) will be a point on the unit circle in the second quadrant. Since it is a unit circle, its radius is 1, and we have
sin(α) = y = 0.6
cos(α) = x = -0.8
tan(α) = y/x = 0.6/-0.8 = -0.75
The angle is α = arccos(-0.8) ≈ 143.13°
______
For the unit circle, the trig values are always the coordinates or their ratio as shown above, regardless of quadrant.
Answer:
308
Step-by-step explanation:
22 x 15.4 = 338.8
338.8 / 1.1 = 308
Answer:
12f-5f²+6f+10f²= 10f²-5f²+12f+6f=5f²+18f
