8(11 + 2r) = 126r + 3
first open the parenthesis
88 + 16r = 126r + 3
88 - 3 = 126r - 16 r
85 = 110r
divide both-side of the equation by 110
85/110 = r
r= 17/22
Standard error of the mean is computed by:
Standard error = SD/ sqrt N
Where:
N is the sample size
SD is the standard deviation
To get the standard deviation, you need to get the sqrt of
the variance = sqrt 9 = 3
So plugging in our data:
Standard error = 3 / sqrt (16)
= 0.75
Answer:
2.351 or 2.4
Step-by-step explanation:
Let the width be X
Then the length is X + 70
The perimeter is the sum of all sides
There are 2 widths (left side and right side) and 2 lengths (top and bottom)
Perimeter = 2 * width + 2 * length
Perimeter = 2 * X + 2 * (X+70)
Perimeter: 2 X + 2 X + 140 = 380
4 X = 380-140
4 X = 240
X = 240 / 4
X = 60
Width = 60 - the smaller of two sides
Length = X + 70 = 60 + 70 = 130 - the larger of two sides
Check:
<span>
2 * 60 + 2 * 130 = 380 </span>
