Which comparison does the ratio 20:21 represent?

Round to nearest thousandth!! (3 decimal places) photo attached

aliina [53]

Answer:

Probability point lies on shaded region: ( About ) 0.294

Step-by-step explanation:

~ If we are to find the probability, we must find the area of the shaded figure, over that of the total area of this trapezoid ( whole figure ) ~

Let us get the general dimensions. Firstly, the base of the trapezoid is composed of parts 5, 12, and 5. This is an isoceles trapezoid, meaning that the triangles ( shaded region ) are congruent to one another, including the altitudes. That would mean the non - shaded region is a parallelogram, provided altitudes are congruent and by definition of a trapezoid the bases are congruent.

1. Given the information above, the smaller base is congruent to the opposite side of the parallelogram created, so it is 12 units in length, the larger base being 12 + 5 + 5 ⇒ 22 units

2. By Pythagorean Theorem, if x ⇒ altitude of one of the triangles ( shaded region), 5^2 + x^2 = 13^2 ⇒ 25 + x^2 = 169 ⇒ x^2 = 144 ⇒ altitude = 12 units

3. Now we can find the area of this trapezoid by: ( base + base/2 ) * altitude ⇒ ( 12 + 22 / 2 ) * 12 ⇒ ( 34 / 2 ) * 12 ⇒ ( 17 ) * 12 ⇒ 204 units^2

5. The shaded region is composed of two triangles, and knowing the triangles are ≅, let us solve for the area of one triangle and multiply that by 2 to find the total area of the shaded region. Area of triangle: 1/2 * base * altitude ⇒ 1/2 * 5 * 12 ⇒ 30 units^2. Area of shaded region: 30 * 2 = 60 units^2

Probability point lies on shaded region: 60/204 ⇒ ( About ) 0.294

8 0

3 years ago

To obtain information on the corrosion-resistance properties of a certain type of steel conduit, 45 specimens are buried in soil

Fiesta28 [93]

Answer:

The sample has not met the required specification.

Step-by-step explanation:

As the average of the sample suggests that the true average penetration of the sample could be greater than the 50 mils established, we formulate our hypothesis as follow

$H_0$ : The true average penetration is 50 mils

$H_a$ : The true average penetration is > 50 mils

Since we are trying to see if the true average is greater than 50, this is a right-tailed test.

If the level of confidence is α = 0.05 then the $z_\alpha$ score against we are comparing with, is 1.64 (this is because the area under the normal curve N(0;1) to the right of 1.64 is 0.05)