1. **State the problem:** We have a binomial distribution with mean $\mu = 6$ and standard deviation $\sigma = \sqrt{2}$. We need to find the first two terms of the distribution, i.e., $P(X=0)$ and $P(X=1)$.
2. **Recall formulas:** For a binomial distribution $X \sim Bin(n,p)$, the mean and variance are given by:
$$\mu = np$$
$$\sigma^2 = np(1-p)$$
where $n$ is the number of trials and $p$ is the probability of success in each trial.
3. **Use given values:**
Given $\mu = 6$ and $\sigma = \sqrt{2}$, so variance $\sigma^2 = 2$.
From the formulas:
$$np = 6$$
$$np(1-p) = 2$$
4. **Find $p$ and $n$:**
From $np = 6$, we get $n = \frac{6}{p}$.
Substitute into variance equation:
$$6(1-p) = 2$$
$$6 - 6p = 2$$
$$6p = 4$$
$$p = \frac{2}{3}$$
Then,
$$n = \frac{6}{2/3} = 6 \times \frac{3}{2} = 9$$
5. **Calculate first two terms:**
The binomial probability mass function is:
$$P(X=k) = \binom{n}{k} p^k (1-p)^{n-k}$$
- For $k=0$:
$$P(X=0) = \binom{9}{0} \left(\frac{2}{3}\right)^0 \left(\frac{1}{3}\right)^9 = 1 \times 1 \times \left(\frac{1}{3}\right)^9 = \left(\frac{1}{3}\right)^9$$
- For $k=1$:
$$P(X=1) = \binom{9}{1} \left(\frac{2}{3}\right)^1 \left(\frac{1}{3}\right)^8 = 9 \times \frac{2}{3} \times \left(\frac{1}{3}\right)^8 = 9 \times \frac{2}{3} \times \frac{1}{3^8} = 6 \times \frac{1}{3^8}$$
6. **Final answers:**
$$P(X=0) = \left(\frac{1}{3}\right)^9$$
$$P(X=1) = 6 \times \left(\frac{1}{3}\right)^8$$
Binomial First Terms 6B0479
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