A graphing calculator working the quadratic regression problem for these three points gives the equation as
y = 2x² +7x -5
The question also states that Lucy has a winning probability of 1/50, which means that she has 1 chance of winning if the total runners were 50. Therefore, there are 49 runners who may be faster than her.
The fact that Lucy is the 50th slowest runner, means that starting from the slowest she is in 50th position, therefore there are 49 runners that are slower than her.
The total number of runners will be the sum of those faster than Lucy, those slower than Lucy and Lucy:
49 + 49 + 1 = 99
There are 99 runners in Lucy's school.
That is impossible but I did some math so there are 2 ways that will equal more than 40.
6.7×6.0=40.2
6.5×6.2=40.3
Hope this helps!
x = population after 3 years
y = starting population
r = percentage
n = number of years
x = y *(1+r)^n
x = 8200 * (1 +0.03)^3
x = 8960.36
so about 8960 people in 3 years
To answer this question, you need to draw out the graph first. By doing so, you will be able to know where the other endpoint is located. (Fig. 1)
Next, count the number from the midpoint to the endpoint to determine the coordinates for the other endpoint. (Fig. 2)
Example: From (2, 5) to (6, 3)
x: 2 to 6 = 4 steps
y: 5 to 3 = 2 steps
From there, you can determine the other endpoint like this.
Example: From (2, 5) to the other endpoint
x: 2 to x1 = 4 steps
y: 5 to y1 = 2 steps
Therefore, x1 = -2 and y1 = 7
Other endpoint: (-2, 7)
Sorry for the messy drawing, it is hard to draw without a pen. Haha... hope this helps :)