Hi,
The answer is c. The sample is biased.
This is because the sample is taken on a single state, an Rebecca reports a statistic about the nation. Her data contains information only of her state. If she lives in a very cold state, there is probably more homeowners using electric heat than in a hot state.
Answer:
Step-by-step explanation:
find the area
The equation of a circle is defined by: (x - h)² + (y - k)² = r² where
(h,k) represents the center of your circle and r = the radius
So (x - 2)² + (y + 8)² = 121 is your equation
Answer: 80 minutes
Step-by-step explanation:
Hi, to answer this question we have to write an equation for each tank:
An empty 1200 gallon tank is filled with water at a rate of 6 gallons of water per minute.
So, the amount of water of the tank is equal to the filling rate, 6 liters per minute (6m)
- Tank 1 =0 (empty )+ 6m =6m
The second 1200 gallon tank full of water is being drained at a rate of 9 gallons per minute.
So, the amount of water in the tank is equal to the amount of water already in the tank (1200 g), minus the draining rate (9m)
Since both tanks will have the same amount of water:
6m = 1200-9m
Solving for m (minutes):
6m+9m= 1200
15m = 1200
m= 1200/15
m= 80 minutes
Feel free to ask for more if needed or if you did not understand something.
7^2 = 6^2 + 9^2 - 2(6)(9)cos(m)
-68 = 2(6)(9)cos(m)
cos(m) = -0.6296
m = arcos ( -0.6296)
m = 129.0 degrees
