1. **Stating the problem:** We want to find the mean and standard deviation of the total money collected from selling adult tickets at 10 each and children tickets at 6 each on a random Saturday, assuming the number of adult and children tickets sold are independent random variables.
2. **Formulas and rules:**
- If $X$ and $Y$ are independent random variables, then the mean of their sum is $E(X+Y) = E(X) + E(Y)$.
- The variance of their sum is $Var(X+Y) = Var(X) + Var(Y)$ because of independence.
- The standard deviation is the square root of the variance: $\sigma = \sqrt{Var}$.
3. **Define variables:**
Let $A$ be the number of adult tickets sold, and $C$ be the number of children tickets sold.
The total money collected is $M = 10A + 6C$.
4. **Calculate mean of $M$:**
$$E(M) = E(10A + 6C) = 10E(A) + 6E(C)$$
5. **Calculate variance of $M$:**
$$Var(M) = Var(10A + 6C) = 10^2 Var(A) + 6^2 Var(C) = 100 Var(A) + 36 Var(C)$$
6. **Calculate standard deviation of $M$:**
$$\sigma_M = \sqrt{Var(M)} = \sqrt{100 Var(A) + 36 Var(C)}$$
7. **Summary:**
- Mean money collected: $E(M) = 10E(A) + 6E(C)$
- Standard deviation: $\sigma_M = \sqrt{100 Var(A) + 36 Var(C)}$
To find numerical values, you need the means and variances of $A$ and $C$ (number of tickets sold).
Ticket Sales Ad69E1
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