Answer:
Step-by-step explanation:
line 1 m=y2-y1 / x2-x1 [formula for slope ]
m= 0 - (-3) / 8-(-4)
m= 3 /12
m= 1/4 slope of line 1
line2
m = 2-6 / 0-(-1)
m = -4 / 1
m = -4 slope of line 2
line 3
m = -4 - (-7) / -3 - 6
m = 3 / -9
m = - 1/3 slope of line 3
lines 1 & 2 perpendicular b/c they are reciprocals with a sign change :)
lines 1 & 3 neither.. differet slopes and not reciprocals
lines 2 & 3 perpendicular b/c they are reciprocals with a sign change :)
58057, 58058, 58059 are the numbers!
Answer:

--- Variance
Step-by-step explanation:
Given

Solving (a): Calculate the mean.
The given data is a grouped data. So, first we calculate the class midpoint (x)
For 51 - 58.

For 59 - 66

For 67 - 74

For 75 - 82

For 83 - 90

So, the table becomes:

The mean is then calculated as:



-- approximated
Solving (b): The sample variance:
This is calculated as:

So, we have:


-- approximated