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 number of children between the ages of 9 and 15 who visited the park is

EXPLANATION
The number of children between the ages of 9 and 15 who visited the park are those within the age group 9 to 12 and 12 to 15.
We can from the graph that, the height of the bar that corresponds to the age group 9 to 12

and the height of the bar that corresponds to the age group 12 to 15

The sum of the two frequencies
The most logical answer would be something like the number of music lovers in the city or something similar. That is because if there are many people loving music, then there are many stations, which means many concerts.
The unit price is : 65.25/9 = 7,25 $