1 step (B): raise both sides of the equation to the power of 2.
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2 step (A): simplify to obtain the final radical term on one side of the equation.
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3 step (F): raise both sides of the equation to the power of 2 again.
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4 step (E): simplify to get a quadratic equation.
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5 step (D): use the quadratic formula to find the values of x.
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6 step (C): apply the zero product rule.
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Additional 7 step: check these solutions, substituting into the initial equation.
Answer:
r = (ab)/(a+b)
Step-by-step explanation:
Consider the attached sketch. The diagram shows base b at the bottom and base a at the top. The height of the trapezoid must be twice the radius. The point where the slant side of the trapezoid is tangent to the inscribed circle divides that slant side into two parts: lengths (a-r) and (b-r). The sum of these lengths is the length of the slant side, which is the hypotenuse of a right triangle with one leg equal to 2r and the other leg equal to (b-a).
Using the Pythagorean theorem, we can write the relation ...
((a-r) +(b-r))^2 = (2r)^2 +(b -a)^2
a^2 +2ab +b^2 -4r(a+b) +4r^2 = 4r^2 +b^2 -2ab +a^2
-4r(a+b) = -4ab . . . . . . . . subtract common terms from both sides, also -2ab
r = ab/(a+b) . . . . . . . . . divide by the coefficient of r
The radius of the inscribed circle in a right trapezoid is r = ab/(a+b).
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The graph in the second attachment shows a trapezoid with the radius calculated as above.
Answer:
This value means that his shoe size is 2.9 deviations above the population mean.
And we can find the approximate percentile for his measure like this:
This correspond to the 99.8 percentile, so then his shoe size is 99.8% above all the shoe sizes.
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the shoe size of a population, and for this case we know the distribution for X is given by:
Where represent the mean and
the population standard deviation.
For this case we know that a man obtain a z score of z=2.9
This value means that his shoe size is 2.9 deviations above the population mean.
And we can find the approximate percentile for his measure like this:
This correspond to the 99.8 percentile, so then his shoe size is 99.8% above all the shoe sizes.
Answer:
B
Step-by-step explanation:
By the definition,
If we can consider right triangle with hypotenuse 25 un. and adjacent leg 24 un. By the Pythagorean theorem,
So,