If the mean is 20.8, one standard deviation each way is adding and subtracting 3.1, so 17.7 and 23.9 (68% of values)
Two standard deviations adding and subtracting 3.1*2 = 6.2, or 14.6 and 27.
Three standard deviations is 11.5 and 30.1
So we have
11.5 - 14.6 - 17.7 - 20.8 - 23.9 - 27 - 30.1
Going left to 11.5 is 3 standard deviations out, so 99.7/2 = 49.85%
Going right to 27 is 2 standard deviations out, so 95/2 = 47.5%
Add those two % to get 97.32%
This is hard to do without a picture so I hope that helps!
X and y are equal to 36.8
Area of square =6*6= 36 cm^2
Area of trapezoid =1/2( base1+base2)*height
base 1=7
base2=21-6=15
height=6
Area of trapezoid =1/2( 7+15)*6= 66
whole area = area of square + area of trapezoid= 36+66=102
Answer 102
The measurements are:
b₁ = 8.4 inches; b₂ = 14 inches; leg₁ = 2.8 inches; leg₂ = 2.8 inches
Let x = length of base and leg
The formula for perimeter of isosceles trapezoid is P = b₁ + b₂ + 2(leg)
Where: b = base
P = b₁ + b₂ + 2(leg)
28 = 3x + 5x + 2(x)
28 = 8x + 2x
28/10 = 10x/10
2.8 = x
Now, substitute the values:
P = b₁ + b₂ + 2(leg)
28 = 3(2.8) + 5(2.8) + 2(2.8)
28 = 8.4 + 14 + 5.6
28 = 28
Hence the measurements are:
b₁ = 8.4 inches; b₂ = 14 inches; leg₁ = 2.8 inches; leg₂ = 2.8 inches