Answer:
Step-by-step explanation:
The way to approach this that makes the most sense to a student would be to find out how far from the house the ladder currently is, then add 3 feet to that and do the problem all over again. This is right triangle stuff...Pythagorean's Theorem in particular. The ladder is the hypotenuse, 52 feet long. The height of the rectangle is the distance the ladder is up the side o the house, 48 feet. We plug those into Pythagorean's Theorem and solve for the distance the ladder is from the house:
and
and
so
x = 20. Now if we add the 3 feet that the ladder was pulled away from house, the distance from the base of the ladder to the house is 23 feet, the ladder is still 52 feet long, but what's different is the height of the ladder up the side of the house, our new x:
and
and
so
x = 46.6 feet
Answer:
The best estimate of the probability of getting a green marble from this bag of 50 marbles is 1/3.
Step-by-step explanation:
Andre gets 1 green marble out of 4 trials.
For Andre, the probability of getting 1 green marble is 1/4.
Jada gets 5 green marbles out of 12 trials.
For Jada, the probability of getting 1 green marble is 5/12.
Noah gets 3 green marbles out of 9 trials.
For Noah, the probability of getting 1 green marble is 3/9.
Hence, the best estimate of the probability of getting a green marble from this bag = (1/4 + 5/12 + 3/9)/3 = [(9 + 15 + 12)/36]/3 = 1/3.
Answer:
Stratified Sampling
Step-by-step explanation:
Since Keri divides the day into different strata and each unit is selected from each strata randomly. So, it is Stratified Sampling.
Further, In Stratified Sampling population is divided into several groups such that within the group it is homogeneous and between the group it is heterogeneous. And now a selection of each stratum and unit has an equal chance of selection.
The sector (shaded segment + triangle) makes up 1/3 of the circle (which is evident from the fact that the labeled arc measures 120° and a full circle measures 360°). The circle has radius 96 cm, so its total area is π (96 cm)² = 9216π cm². The area of the sector is then 1/3 • 9216π cm² = 3072π cm².
The triangle is isosceles since two of its legs coincide with the radius of the circle, and the angle between these sides measures 120°, same as the arc it subtends. If b is the length of the third side in the triangle, then by the law of cosines
b² = 2 • (96 cm)² - 2 (96 cm)² cos(120°) ⇒ b = 96√3 cm
Call b the base of this triangle.
The vertex angle is 120°, so the other two angles have measure θ such that
120° + 2θ = 180°
since the interior angles of any triangle sum to 180°. Solve for θ :
2θ = 60°
θ = 30°
Draw an altitude for the triangle that connects the vertex to the base. This cuts the triangle into two smaller right triangles. Let h be the height of all these triangles. Using some trig, we find
tan(30°) = h / (b/2) ⇒ h = 48 cm
Then the area of the triangle is
1/2 bh = 1/2 • (96√3 cm) • (48 cm) = 2304√3 cm²
and the area of the shaded segment is the difference between the area of the sector and the area of the triangle:
3072π cm² - 2304√3 cm² ≈ 5660.3 cm²
