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.
Answer:
No Solution
Step-by-step explanation:
8x+15=8x (2 times 4x equals 8x)
15=0 (Move the 8x to the other side)
No Solution (15 can't be equal to 0)
Answer:
B. 2/3
Step-by-step explanation:
To solve this we have to take into account this axioms:
- The total probability is always equal to 1.
- The probability of a randomly selected point being inside the circle is equal to one minus the probability of being outside the circle.
Then, if the probabilities are proportional to the area, we have 1/3 probability of selecting a point inside a circle and (1-1/3)=2/3 probability of selecting a point that is outside the circle.
Then, the probabilty that a random selected point inside the square (the total probability space) and outside the circle is 2/3.
Answer:
20 mph and 4 mph
Step-by-step explanation:
GIVEN: A boat travels upstream for 
miles in 
hours and returns in 
hours traveling downstream in a river.
TO FIND: What is the rate of the boat in still water and the rate of the current.
SOLUTION:
Let the speed of boat in still water be 
and speed of current be 
.
speed of water in upstream 
speed of water in downstream 
As 
Solving both we get
Hence speed of boat in still water and rate of current is 20mph and 4mph respectively.
<span>