Answer:
D
Step-by-step explanation:
Let x be Bill’s scores.
Let y be Theo’s scores.
x + y = 90
x² = y
Solve for x in the second equation.
x = √y
Put x as √y in the first equation and solve for y.
√y + y = 90
√y = 90 - y
y = (90 - y)²
y = - y² - 180y - 8100
0 = -y² - 181y - 8100
0 = (-y+81)(y-100)
-y+81=0
y = 81
y - 100 = 0
y = 100
100 does not work if we plug in to check, so y is 81.
y = 81
Put y as 81 in the first equation and solve for x.
x + 81 = 90
x = 9
Bill scored 9 goals and Theo scored 81.
Answer:
8)55°
9)35°
10)55°
11)69°
12)64°
Step-by-step explanation:
8)180-125=55
9)90-55=35
10)180-125=55
11)180-111=69
12)45+69=116
180-166=64
D.) 9,987,000 becomes 9.987 x 10^6
Answer:
This sampling technique is called cluster
Step-by-step explanation:
Samples may be classified as:
Convenient: Sample drawn from a conveniently available pool.
Random: Basically, put all the options into a hat and drawn some of them.
Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.
Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.
In this question:
The population is divided into groups(by stores), and all elements of the groups(all customers at the stores are sampled), which is the characteristic of a cluster sampling.
Notice the tickmark on the angles, those angles are equal to each other.
now, notice the angle at the very top, the large triangle is really sharing it with smaller-inscribed triangle, and therefore is equal on both triangles.
therefore, the larger triangle, is similar with smaller-inscribed triangle by AA.
what the dickens does that mean?