Answer:
the required answer is 64
Step-by-step explanation:
b/4 =16
b = 16 × 4
= 64
This is my answer - a beautiful image. You haven’t attached the image to determine the answer, please do!
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
1500x1.04^6=£1898 to the nearest whole number
The cosine of A is (adjacent side)/(hypotenuse) = 55/73. Do the division, then find the angle whose cosine is that number. The whole thing takes maybe 6 or 7 seconds with your calculator. It's choice-B.
