Answer:
Plane Speed (x) = 378 mph
Step-by-step explanation:
Equation
d = r * t
Givens
With the wind
- d = 1680 miles
- t = 4 hours
- r = x + y
Against the wind
- d = 1680
- t = 5 hours
- r = x - y
Equation
The distances are the same, so you can solve for x in terms of y and then deal with the actual distance.
(x + y)*4 = (x - y)*5 Remove the brackets on both sides
Solution
- 4x + 4y = 5x - 5y Subtract 4x from both sides
- 4y = -4x + 5x - 5y Combine
- 4y = x - 5y Add 5y to both sides
- 5y + 4y = x
- x = 9y
Solution part 2
Now take one of the distance formulas and solve for x first then y.
- (x - y)*5 = 1680 Substitute 9y for x
- (9y - y)*5 = 1680 Subtract on the left
- 8y * 5 = 1680 Multiply on the left
- 40y = 1680 Divide by 40
- y = 1680/40
- y = 42 That's the speed of the wind.
- (x - y)*5 = 1680 Substitute the wind speed for y
- (x - 42)*5 = 1680 Divide both sides by 5
- (x - 42) = 1680 / 5 Do the division on the right
- (x - 42) = 336 Add 42 to both sides.
- x = 336 + 42
- x = 378 mph Plane's speed
Answer:
119
Step-by-step explanation:
Answer:
D
Step-by-step explanation:
The mean of a standard normal distribution is always = 0 with the standard deviation being equal to. Therefore a standard normal distribution is a normal distribution described with a mean of 0 and standard deviation of 1. Since a standard normal distribution is centered at the middle with equal distribution to both the left and right of the distribution. The centre point is 0, which is the mean and the standard deviation is 1 to either side of the distribution.
Answer:
1?
Step-by-step explanation:
I think its one...
