Answer: Top right and left are ACUTE, Bottom right is RIGHT, and bottom left is OBTUSE.
Answer: Choice B
There is not convincing evidence because the interval contains 0.
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Explanation:
The confidence interval is (-0.29, 0.09)
This is the same as writing -0.29 < p1-p1 < 0.09
The thing we're trying to estimate (p1-p2) is between -0.29 and 0.09
Because 0 is in this interval, it is possible that p1-p1 = 0 which leads to p1 = p2.
Therefore, it is possible that the population proportions are the same.
The question asks " is there convincing evidence of a difference in the true proportions", so the answer to this is "no, there isn't convincing evidence". We would need both endpoints of the confidence interval to either be positive together, or be negative together, for us to have convincing evidence that the population proportions are different.
So x + y = 45, and 4x + 5y = 195. Get y by itself. Subtract x from both sides in the first equation to get y = 45 -x, and subtract 4x from the second equation to get 5y = 195 - 4x. Divide by 5 to both sides to get y = 39 - 4/5x. 39 - 4/5x = 45 - x. Add x to both sides to get 39 - 1/5x = 45. Subtract 39 from both sides to get -1/5x = 6. Divide by -1/5 to get x = -30, or 30. In the first equation, do 30 + y = 45. Subtract 30 from both sides to get y = 15. Check. 4(30) + 15(5) = 195, or 120 + 75 = 195.
T1/2 = ln 2 / k = ln 2 / 0.125 = <span>5.5</span>
