Answer:
20 minutes on the stationary bike
10 minutes on the treadmill
Step-by-step explanation:
x = minutes on bike
y = minutes on treadmill
x + y = 30
12x + 15y = 390
x = 30-y
12(30-y) + 15y = 390
360 - 12y + 15y = 390
3y = 30
y = 10
x + 10 = 30
x = 20
Rate of change is 4. change of y over change of x= 20/5
9514 1404 393
Answer:
(18 1/48)π ≈ 56.61 units
Step-by-step explanation:
Arc length is the product of radius and intercepted arc in radians:
s = rθ
s = (21 5/8)(5π/6) = (18 1/48)π ≈ 56.61 . . . units
Answer:
a. 81.5%
Step-by-step explanation:
The z-score for 400 is ...
Z = (X -μ)/σ = (400 -500)/100 = -1
The z-score for 700 is ...
Z = (700 -500)/100 = 2
The empirical rule tells you that 68% of the distribution is within ±1σ of the mean, and 95% is within ±2σ of the mean. Half of that first number is in the range Z = -1 to 0, and half that second number is in the range Z = 0 to +2. So, the probability you want is ...
(1/2)(68%) + (1/2)(95%) = 81.5% . . . . matches choice A
