If he runs 6 mph for 1.5 hours, he will run a total of 9 miles
Given function: f(x) = (3x+5)/7
y = f(x) so it's the same as y = (3x+5)/7
Swap every copy of x and y to get x = (3y+5)/7
Solve for y to get....
x = (3y+5)/7
7x = 7*(3y+5)/7
7x = 3y+5
7x-5 = 3y+5-5
7x-5 = 3y
3y = 7x-5
3y/3 = (7x-5)/3
y = (7x-5)/3
So the inverse function is f^(-1)(x) = (7x-5)/3
Answer is choice A
C
Hope I helped! :-)
~Sequoyah! :-)
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
