Answer:
0.33 with the bar on top
Step-by-step explanation:
Answer:
-6x +10x= 4x
Step-by-step explanation:
-2x(3 - 5x)
-6x +10x= 4x
What you need to do is find a common multiple which is 11, Then you divide 22c and 33d by 11 so you get 2c and 3d Then since there is an addition sign you put 2c and 3d is ()
The Final answer is
11(2c+3d)
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
The answer to this problem is =x