"apply quickselect to find the median of the list of numbers 9, 12, 5, 17, 20, 30, 8."

12

Step-by-step explanation:

In statistics, the median is the value that separates the higher half from the lower half of a data sample. This means that it is the "middle" value of a data sample. In order to find the median, you need to place the numbers of your data sample in order of value, and identify the middle point. If two sets of numbers are in the middle, then you need to find the middle point between the two (by adding them and then dividing them by two).

Therefore:

5, 8, 9, 12, 17, 20, 30

18 units²

step-by-step explanation:

first let's find altitude bd using the distance formula

d = √((y₂ - y₁)² + (x₂ - x₁)²)

bd = √((0 - -3)² + (0 - 3)²)

bd = √18

given the placement of points a and c, we can denote that point d bisects segment ac.

we will call ac the base.

using the distance formula

ac = √((0 - 6)² + (-6 - 0)²)

ac = √72

knowing our base and our height, we can plug these into our triangle area formula

area = (b * h)/2

area = (√18 * √72) / 2

area = (√1296) / 2

area = 36 / 2

area = 18 units²