C. formula
I hope this helps, thank you.
Let's call our estimate x. It will be the average of n IQ scores. Our average won't usually exactly equal the mean 97. But if we repeated averages over different sets of tests, the mean of our estimate the average would be the same as the mean of a single test,
μ = 97
Variances add, so the standard deviations add in quadrature, like the Pythagorean Theorem in n dimensions. This means the standard deviation of the average x is
σ = 17/√n
We want to be 95% certain
97 - 5 ≤ x ≤ 97 + 5
By the 68-95-99.7 rule, 95% certain means within two standard deviations. That means we're 95% sure that
μ - 2σ ≤ x ≤ μ + 2σ
Comparing to what we want, that's means we have to solve
2σ = 5
2 (17/√n) = 5
√n = 2 (17/5)
n = (34/5)² = 46.24
We better round up.
Answer: We need a sample size of 47 to be 95% certain of being within 5 points of the mean
C is the answer i thinkkk
Answer : y - 1 = 1/2 (x-3)
The formula for point slope is y - y1 = m (x - x1)
M is the slope of the line. The nine and three come from the point given. I used the point (3, 1). Hope this helps !
Answer:
X=40°
X=30°
X=50°
Step-by-step explanation:
Let our unknown angles be denoted by 
Part I
We are given the sum of the angles as 70°, the known as 30° and the unknown as X;
To find X, we subtract the known angle from the sum as:
X=70°-30°=40°
Hence X= 40°
Part II
We are given the sum of the angles as 70°, the known as 40° and the unknown as X;
To find X, we subtract the known angle from the sum as:
X=70°-40°=30°
Hence X= 30°
Part III
We are given the sum of the angles as 80°, the known as 30° and the unknown as X;
To find X, we subtract the known angle from the sum as:
X=80°-30°=50°
Hence X= 50°
