The answer is b.
This is because the line is sloping downwards, and so y = -1
Answer:
-7
Step-by-step explanation:
Answer:
System of equations:
20x + 30y = 650
x + y = 25
Time underwater = 10 hours
Time at the surface = 15 hours
Step-by-step explanation:
Let x = time underwater at 20 km/h.
Let y = time on the surface at 30 km/h.
speed = distance/time
distance = speed * time
distance underwater: 20x
distance on the surface: 30y
total distance: 650
20x + 30y = 650
total time: x + y
total time: 25
x + y = 25
20x + 30y = 650
x + y = 25
20x + 30y = 650
-20x - 20y = -500
--------------------------------
10y = 150
y = 15
x + y = 25
x + 15 = 25
x = 10
Answer:
Step-by-step explanation:
I know that the two means are are 11.28 and 12.
I could be wrong but I did the math 5 times.
Answer:
a) The variable of the study is: milligrams of nitrogen per liter of water.
This is the amount that needs to be measured and analyzed to reach conclusions in the study.
b) The variable is quantitative. The quantitative variables are those that represent quantities. This variables can be measured on a continuous or discrete scale. Then, all the variables that you can measure or count are quantitative variables(height of trees, number of passengers per car, wind speed, milligrams of nitrogen per liter, etc). On the other hand, qualitative variables are those that can’ t be measured, and they represent attributes, like apple colors (red, green), size of trousers (small, medium, large) and so on.
c) The population under study is the milligrams of nitrogen per liter of water that are in the entire lake. You can estimate the parameters of the population by taking samples (In the example, 28 samples are taken).
