The reason for statement 4 is CPCTC.
for 6
in a
given
slope(m)=1
point=(2,-4)=(x1,y1)
we know
equation of straight line
y-y1=m(x-x1)
y+4=1(x-2)
y+4=x-2
therefore x-y-6=0 is the required equation
substituting with ax+by+c=0 we get
a=1
b= -1
c= -6
The outlier is 3, and the outlier has a greater effect on the mean because it is an average of all numbers where as the median is just the middle value in the data set. Everything else you can do on your own. To find the mean you add all the numbers up and divide by the total amount of numbers there are, the median you just cross one out from the left and then cross one out from the right and continue doing this until you are left with one number, or if you are left with two numbers you can add those two numbers up and then divide them by 2
In any trapezoid, the area is given by

where B and b are the two bases, and h is the height. You're given all these elements already, so you only need to plug the values in:
