6(x-2.5) ≥ 8-6(3.5+x)
A number is before a parenthesis. The first step is to multiply.
6(x-2.5) = 6x -15
8-6(3.5+x)
2(3.5+x)= 7+2x
6x-15≥7+2x
Now solve
6x-15≥7+2x
-2x -2x
(-2x+2x)= They cancel out
(6x-2x)= 4x
4x-15≥7
+15 +15
4x≥22
/4 /4
You get= x≥5.5
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:
C) fails to consider that commuting trips may cause significantly more than 20 percent of the traffic congestion
Step-by-step explanation:
The correct option is - C) fails to consider that commuting trips may cause significantly more than 20 percent of the traffic congestion
Reason -
Option A is incorrect because the statistics can not be incorrect.
Option B is incorrect because they are not talking about the city.
Option C is correct because Urban rail reduces congestion.
Option D is incorrect because the opposers cited the example of one city and the supporters are presenting evidence in the case of that city itself.
Option E is incorrect because they are providing an explanation for why the commuters data given by opposers is not relevant. The opposers talked about commuters.
Answer: B. False
Distance between points is square root of (x1 - x2) + (y1 - y2).
Hope it helped!
