Answer:
8.2+/-0.25
= ( 7.95, 8.45) years
the 95% confidence interval (a,b) = (7.95, 8.45) years
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = 8.2 years
Standard deviation r = 1.1 years
Number of samples n = 75
Confidence interval = 95%
z value(at 95% confidence) = 1.96
Substituting the values we have;
8.2+/-1.96(1.1/√75)
8.2+/-1.96(0.127017059221)
8.2+/-0.248953436074
8.2+/-0.25
= ( 7.95, 8.45)
Therefore the 95% confidence interval (a,b) = (7.95, 8.45) years
Well, to find u, we have to remove all that is attached to it so the equation can just be u=...
To find u, you have to remove what is attached to it, and that is -12. Then you have to look at the relationship between the -12 and u. The relationship is multiplication, and the opposite of multiplication is division, so all you have to do is divide both sides by -12. So;
-12u/-12=-24/-12
The -12 cancels the -12, leaving u and the - in 12 cancels the - in 24. Leaving 24/12. And that is 2. Written as;
u=2
Hope i helped. If you have any more problems, let me know.

y = 2 + x^6
y - 2 = x^6
x = (y - 2)^1/6

Well, solving this integral
= 2,69279