<span>2n^2 - 7n - 3 = 0
a = 2
b = -7
c =-3
Then use the Quadratic formula:
x = [-b +-sqroot(b^2 -4*a*c)] / 2*a
</span>
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
Let's say <span>Mr.rodrigues's total amount of money is x. 1/2 of his money is in land, 1/10 of his money is in stocks, and 1/20 of his money is in bonds. The remaining is in his savings. Therefore, 1-1/2-1/20-/10 = fraction of money in savings account = 35/100 = 7/20. If 7/20 of his money =35000, then we can say that (7/20)x=35000, and 35000*20=7x, then getting (35000*20/7)=x, which equals (5000*20)=100,000 dollars.</span>
270 divided by 3 = 90.
90 is the cost per person.
Now you do 90 times 10 to get the total for all 10 people.
90 times 10= 900.
