The answer is 5.5
The standard deviation (sd or σ) of the sample mean difference is:
sd = √(sd₁²/n₁ + sd₂²/n₂)
For the population A:
sd₁ = 17.6
n₁ = 25
For the population B:
sd₂ = 21.2
n₂ = 30
Hence:
sd = √(sd₁²/n₁ + sd₂²/n₂)
= √(17.6²/20 + 21.2²/30)
= √(309.76/20 + 449.44/30)
= √(15.49 + 14.98)
= √(30.47)
= 5.5
SOH CAH TOA
CAH
Cosine = Adjacent / Hypotenuse
∆ABC, where lets say B is the right angle.
cos C = adjacent/hypotenuse = BC/AC
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Answer:
6.4
Step-by-step explanation:
In ΔVWX, the measure of ∠X=90°, the measure of ∠W=9°, and WX = 8.7 feet. Find the length of XV to the nearest tenth of a foot.
The scale means every 1 inch is really equal to 20 inches.
so the 4X5 room is actual 4(20)X5(20)
80X100
Area = 80X100
Area = 8000 square inches.
It wants square feet though.
For that you simply divide by 144 (since there are 12 inches in a foot for length and 12 inches in a foot for width).
8000/144= 55.55 Square Feet
You could also covert inches to feet before calculating area
Remember it was 80inchesX100inches
80/12=6.66feet
100/12=8.33feet
6.66X8.33= 55.55 square feet
Works both ways.