Answer: 10 percent
Step-by-step explanation:
because she was supposed to do 40 she did only 12 so it is 10%
Answer:
y = 60x + 20
Step-by-step explanation:
The number of hours that we ski is a variable cost where each hour costs $60. On top of that, we have a fixed cost of $20 which stays the same no matter how long we ski.
So we can use an equation to find the totla cost C given the number of hours t as follows:
C(t) = 60t + 20
We can use this equation to find the cost of a skiing session by plugging in some value for t. For example, if we ski for 3 hours:
C(3) = 60(3) + 20 = $200
The equation can also be written using x and y and mean the same thing.
Answer:
μ ≈ 2.33
σ ≈ 1.25
Step-by-step explanation:
Each person has equal probability of ⅓.
![\left[\begin{array}{cc}X&P(X)\\1&\frac{1}{3}\\2&\frac{1}{3}\\4&\frac{1}{3}\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7DX%26P%28X%29%5C%5C1%26%5Cfrac%7B1%7D%7B3%7D%5C%5C2%26%5Cfrac%7B1%7D%7B3%7D%5C%5C4%26%5Cfrac%7B1%7D%7B3%7D%5Cend%7Barray%7D%5Cright%5D)
The mean is the expected value:
μ = E(X) = ∑ X P(X)
μ = (1) (⅓) + (2) (⅓) + (4) (⅓)
μ = ⁷/₃
The standard deviation is:
σ² = ∑ (X−μ)² P(X)
σ² = (1 − ⁷/₃)² (⅓) + (2 − ⁷/₃)² (⅓) + (4 − ⁷/₃)² (⅓)
σ² = ¹⁴/₉
σ ≈ 1.25
As y varies directly with x, there is a proportionality constant. As x increases by that certain constant, y also increases. We equate:
y = kx
where k = proportionality constant.
Given the condition, y = 5 when x = 4, then we solve for k:
5 = k(4)
k = 5/4 or 1.25
When y = 8, then
8 = (5/4)(x)
x = 8/(5/4) = (8)(4/5) = 32/5 or 6.4 (ANSWER)
