If you need to find x. The answer is x=1/-2. Hope this helps!
Answer:
b. =8.5+1.96*3/SQRT(45), and =8.5-1.96*3/SQRT(45)
Step-by-step explanation:
Sample size (n) = 45
Sample mean (M) = 8.5 minutes
Variance (V) = 9 minutes
Z-score for a 95% confidence interval (z) = 1.96
A confidence interval is defined by the following expression:

Applying the given data:

Writing in Excel statements, the limits of the interval would be
=8.5+1.96*3/SQRT(45), and =8.5-1.96*3/SQRT(45)
Therefore, the answer is alternative b.
Answer:
9
Step-by-step explanation:
This is a right triangle. We can use the Pythagorean theorem to determine the missing side.
a^2 + b^2 = c^2 where a and b are the legs and c is the hypotenuse
a^2 + 12 ^2 = 15^2
a^2 +144 =225
a^2 = 225-144
a^2 = 81
Taking the square root of each side
a = 9
Could I get a brainliest award for the first time ?