Answer:
Cluster sample
Step-by-step explanation:
This is an example of a cluster sample. In a cluster sample, the examiner divides the population into groups (each one of these groups is called a cluster) and once the examiner has these clusters, takes one of them and recollects the data from ALL the members of that cluster. In this case, the teacher divided the class in 3 different groups and then selects one of these groups and asks the average amount of time per week he/she spent studying.
<span> To get an explicit formula, we need to find an expression which gives the n-th term without having to compute earlier terms in the sequence. Looking at the numbers, and from the recursive formula, we see that the sequence is built by subtracting n from the previous term. This is similar to the triangular number sequence 1,3,6,10,15,... which has the explicit formula a_n = n(n+1)/2. In our case we are subtracting n from the previous term, so we multiply by -1/2 instead of 1/2. However, we also need to add a constant term to reproduce the numbers of the sequence. We can write a_1 = -1(2)/2 + c = 8. Therefore, c = 9.
So the explict formula is:
a_n = -n(n+1)/2 + 9</span>
Answer:
A 18%
Step-by-step explanation:
I believe it should be A because there is no specific type a marble specified therefore if you do
12/33--> 0.36 times 100= 36 % which isn't an option
15/33->0.45 times 100= 45 % which also isn't an option
6/33= 0.18 times 100= 18% this is the only option given
Volume of a cone = π r² h/3
I envisioned a cone inside a cube. I only identified the necessary value to compute for the exact volume of the largest cone.
Edges of the cube is 10 inches. When the circle part of the cone is placed in the circle, the diameter would be 10 inches also. I divided it by 2 to get the value of the radius, resulting to 5 inches.
The height of the cone is also the height of the cube. Thus, it is 10 inches.
Volume of the cone = 3.14 * (5in)² * 10in/3
V = 3.14 * 25in² * 3.33 in
V = 261.405 in³ or 261.41 in³ VOLUME OF THE LARGEST CONE THAT CAN FIT IN A 10 INCH CUBE
Answer:
x = 10
Step-by-step explanation:
To find x, write a proportion between the side lengths for the similar triangles in the figure.
To solve, cross multiply and isolate x.
(x+5)(12) = 18(x)
12x + 60 = 18x
60 = 6x
10 = x