Answer:
A, B and C are placeholders for constants. (x and y are variables)
The value of a correlation coefficient ranges between -1 and 1.
The greater the absolute value of the Pearson product-moment correlation coefficient, the stronger the linearrelationship.
The strongest linear relationship is indicated by a correlation coefficient of -1 or 1.
The weakest linear relationship is indicated by a correlation coefficient equal to 0.
A positive correlation means that if one variable gets bigger, the other variable tends to get bigger.
A negative correlation means that if one variable gets bigger, the other variable tends to get smaller.
therefore
d is correct
-0.9
<span>x = 25
(x – 7)2 = 36
(x*2) - (7*2) = 36 : multiply x*2 and 7*2 because of distributive property
2x - 14 = 36 : multiply
2x = 36 + 14 : add 14 to combine like terms
2x = 50 : add
x = 50/2 : divide 50 by 2 to get x alone
x = 25 : simplify </span>
According to the geometry program used to draw the triangle, the lengths of the sides add to 21.841 units*. Rounded to the nearest tenth, the appropriate answer choice is ...
... 21.8
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You can use your test-taking skill to choose this answer without doing a single calculation. The answer choices appear to be about rounding, not about accurate calculation of the length. The choice 21.84 tells you that is probably the value before any rounding. Then choices 22 and 21.9 are obviously incorrectly rounded. The correctly rounded answer is then 21.8.
Coordinate differences are ...
AB = (-1, 6) -(-4, 0) = (3, 6) . . . . ║AB║=√(3²+6²)=3√5
BC = (3, -1) -(-1, 6) = (4, -7) . . . . ║BC║=√(4²+7²)=√65
CA = (-4, 0) -(3, -1) = (-7, 1) . . . . ║CA║=√(7²+1²)=5√2
The sum of these lengths is about 21.8415, so rounds to 21.8.
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* If you follow the math, you find that the final sum should be displayed using 3 decimal digits as 21.842. The error in the least-significant digit of the sum comes from rounding each length to 3 decimal digits.