Answer:
A parabola has the form:
y = a*x^2 + b*x + c
Where a is the leading coefficient.
If a is positive, the parabola opens up.
If a is negative, the parabola opens down.
a is the factor that multiplies the part that grows the fastest in the equation, thus, if a is a larger value (in absolute value) then the parabola will grow faster (then the parabola will be narrow)
if a is smaller (again, in absolute value) the parabola will grow slower, then the parabola will be wider.
With this, we can conclude that:
a = -4
is the largest value of a in absolute value.
Then this corresponds to the thinner parabola (the one at the left)
a = -1
Is the middle value of a, then this corresponds to the graph of the middle
a = -0.25
Is the smallest absolute value of a, then this one corresponds to the widest graph (the first one at the left)
to write one thank you card it takes 1/16 of an hour
1 card * 3/4 hour
-------- --------- = the hours cancel and you are left with cards
1/16 hour 1
3/4
------ copy dot flip
1/16
3/4 * 16/1
12 cards
Step-by-step explanation:
D=9
A=pie*radius^2
=3.14*9/2*9/2
=63.58
=64
Answer:
Standard error
Step-by-step explanation:
The standard deviation of the distribution of sample means is called the standard error of the means.
It is denoted by: 
The standard error is calculated using the formula: 
where n is the sample size and 
is the population standard deviation.
Since angle 4x and 8x look like supplementary angles 4x+8x=180°. After solving that equation x=15. Plug that number in and 4x=60° and 8x=120°
