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
y = 1(x +1) - 3
Explanation
A quadratic equation of the form y = ax^2 + bx + c
This written in complete the square form provides you with the vertex (either a maximum or minimum point depending on the equation).
This results in y = a(x + p) + q
Where - p is the x value and q is the y value of turning point.
For graph 22, x = -1 and y = -3
Therefore, the equation is of the form
y = a(x + 1) - 3 (*)
We still need the value a, this can be obtained by using the y-intercept we are given.
We are told x = 0 when y = -2
Substitute this in (*) equation:
-2 = a(0+1) - 3
-2 = a - 3
a = 1
Therefore final equation is
y = 1(x +1) - 3
This should provide you with the train of thought of how the second question should also be tackled.
If unsure about why the equation
y = a(x + p) + q gives the vertex ask in comments I will respond
The abscissa of the ordered pair, that is the x-coordinate, is equal to 1 and the ordinate, the y-coordinate, is equal to -1. In the cartesian plane, this point lies in the fourth (IV) quadrant. The standard position of the angle is that which has one of its side is in the x-axis.
Solve for the hypotenuse of the right triangle formed.
h = sqrt((-1)² + (1)²) = √2
Below items show the calculation for each of the trigonometric functions.
sin θ = opposite/hypotenuse = y/h = (-1)/(√2) = -√2/2
cos θ = adjacent/hypotenuse = x/h = (1)/√2 = √2/2
tan θ = opposite/adjacent = y/x = -1/1 = -1
Answer:
The answer is below
Step-by-step explanation:
Let x represent the cost of 1 scoop of ice cream. Since the cost of 2 scoops of ice cream are twice the price of 1 scoop of ice cream, therefore the cost of 2 scoops of ice cream = 2x
Jean buys 4 tubs with 2 scoops in them and 2 tubs with 1 scoop each. Therefore the money spent by Jean is:
Money spent by Jean = 4(2x) + 2(x) = 8x + 2x = 10x
Sarah buys 2 tubs of 2 scoops and 4 tubs of 1 scoop. The money spent by Sarah is:
Money spent by Sarah = 2(2x) + 4(x) = 4x + 4x = 8x
Sarah spends 2.50 € less than Jean. Therefore:
Money spent by Sarah = Money spent by Jean - 2.5
8x = 10x - 2.5
2x = 2.5
x = €1.25
Therefore the cost of 1 scoop of ice cream is €1.25, the cost of 2 scoops of ice cream is €2.50.
Money spent by Jean = 10x = 10(1.25) = €12.5
Money spent by Sarah = 8x = 8(1.25) = €10
Missing informations but this can be turned into y=4x-12
