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
Answer:
The equation has no real solutions. It has 2 imaginary, or complex solutions.
Step-by-step explanation:
Hello there! The missing y-values are 12, 14, and 16.
Given all our x-values and two additional y-values, we can see that multiplying the x-value by 2 gives us the y-value. This is shown when x is 5 and 9, because multiplying 5 by 2 gave us 10, and multiplying 9 by 2 gave us 18. Because of this rule, we can multiply each given x-value by 2 to receive our y-value. Once solving, we also notice that the y-values all add by 2 to get the next factor as the data number increases. Hope this helps!
Answer:
i dont kknow
Step-by-step explanation:
False, pictures are used in picture graphs or pictographs
