Answer: option D
Step-by-step explanation:
The formulae for standard error = standard deviation/√n
But population standard deviation = 1.8 and sample size = n = 81
Standard error = 1.8/√81 = 1.8/9 = 0.2
Answer:
k = 11
Step-by-step explanation:
Given the points are collinear then the slopes between consecutive points are equal.
Using the slope formula
m = 
with (x₁, y₁ ) = (5, 1) and (x₂, y₂ ) = (1, - 1)
m =
=
= 
Repeat with another 2 points and equate to 
with (x₁, y₁ ) = (1, - 1) and (x₂, y₂ ) = (k, 4)
m =
, then
=
( cross- multiply )
k - 1 = 10 ( add 1 to both sides )
k = 11
Ok so its 50, -7.6, -7.64. then -157 divided by 20
The perimeter will be the perimeter of the real thing divided by 1.2 .
The area will be the area of the real thing divided by (1.2)² .