Answer:
1) Is more representative
Step-by-step explanation:
The problem with his selection is that maybe there are few students participating in certain sport and those students maybe do quite more excercise than the rest (or quite less). This will modify the results because the sample he selected is biased. This problem wont be solved by method 3 or 4, because he is still selecting students that may modify heavily the results with a high probability
This problem will also appear if he choose a sample by class. Maybe, in a class there are quite few students, and selecting from class will make those students appear quite more often than, lets say, a 7th grade student selected at random, therefore the selection is biased in this case as well.
If he has a list with all seventh grade students, each student is equallly likely to be selected and as a consequence, the the results wont be biased. Approach 1 is the best one.
Volume of the candle:
V = B * h ( where B is the base area and h is the height )
270 = B * 18
B = 270 : 18
B = 15 cm²
B = a * b / 2
B = 5 * b / 2
15 = 2.5 b
b = 15 : 2.5
b = 6 cm
Therefore dimensions of the box are: a = 7cm, b = 6 cm, c = 18 cm.
Answer: B ) 7 by 6 by 18 cm.
Work shown above! x = 117 degrees
Answer:
x=3
Step-by-step explanation:
Because DE // AC
so DB/BE = DA/EC
x+5/4=2x/3
4(2x)=3(x+5)
8x=3x+15
5x=15
x=3
Answer:
The radius = 4
Step-by-step explanation:
considering the equation

As the standard form of the circle is

Match the values in this circle to those of the standard form.
- The variable
represents the radius of the circle,
represents the x-offset from the origin, and
represents the y-offset from origin.




Therefore, the radius = 4