Answer:
a) 
And we can conclude that we are 95% confident that the true mean of Co2 level is between 608.29 and 700.03 ppm
b) 
Step-by-step explanation:
Part a
The confidence interval for the mean is given by the following formula:
(1)
In order to calculate the critical value 
we need to find first the degrees of freedom, given by:
Since the Confidence is 0.95 or 95%, the value of 
and 
, and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,51)".And we see that 
Replacing we got:
And we can conclude that we are 95% confident that the true mean of Co2 level is between 608.29 and 700.03 ppm
Part b
The margin of error is given by :
(a)
The desired margin of error is ME =50/2=25 and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025;0;1)", and we got 
, and we use an estimator of the population variance the value of 175 replacing into formula (b) we got:
Answer:
x = 20
Step-by-step explanation:
The two angles are complementary angles, which means they add to 90 degrees
2x+7 + 43 = 90
Combine like terms
2x+50 = 90
Subtract 50 from each side
2x+50-50 = 90-50
2x = 40
Divide each side by 2
2x/2 = 40/2
x = 20
Answer:
238 mm
Step-by-step explanation:
11x5 = 55
11x4=44
11x5=55
11x4=44
4x5=20
4x5=20
______(Add all up)
= 238 mm
Hope this helps :)
Answer:
10×3=30 so the area is 30 square feet
Answer:
This is Isosceles Right
Step-by-step explanation:
An Isosceles is a triangle that has two sides the same length and one side longer or shorter
An Right is an triangle with a 90˚
Hope this helps!
