2x + y = 3
3x - y = 12
Add both equations
5x = 15, x = 3
2(3) + y = 3
6 + y = 3, y = -3
Solution: x = 3, y = -3... or (3,-3)
Falling at the rate of 2.5 m/s for 45 seconds, the anchor fell
(2.5 m/s) x (45 s) = 112.5 meters .
If it wound up only 40 meters underwater, then it must have fallen
(112.5 m - 40 m) = 72.5 meters
from its storage position on the big cruise ship,
before it ever reached the water.
Since it was falling at the rate of 2.5 m/s, it took
(72.5 m) / (2.5 m/s) = 29 seconds
to get down to the water surface after it started dropping.
Answer:
437.4 meters squared
Step-by-step explanation:
7.2*4.5=32.4=b
3*4.5=13.5=h
b*h=a
32.4*13.5=437.4m^2
So the mean is 72.97
We need to subtract the mean from each value and square it.
(65-72.97)^2= 63.5209
(68-72.97)^2=24.7009
(69-72.97)^2=15.7609
(70-72.97)^2=8.8209
(71-72.97)^2= 3.8809
(72-72.97)^2=0.9409
(90-72.97)^2=290.0209
(95-72.97)^2=485.3209
Now we add up the new values ( also consider their frequency) and find their mean.
Add the values
63.5209+(2 •24.7009=49.4018)+(5•15.7609=78.8045)+(8•8.8209=70.5672)+(7•3.8809=27.1663)+(3•0.9409=2.8227)+(2•290.0209=580.0418)+(2•485.3209=970.6418)= 1,842.967
Divide by total numburs to find the mean
1,842.967/ 30=61.43223333
The standar deviation is the square root of the mean so is
Square root of 61.43223333=7.837871735
Round to the nearest tenth
Standard Deviation is 7.8