Question

3 A random of sample of size 25 is taken with replacement from a population with 121.4 and 50.5. 4. A random sample of 20 independent observations is taken from a population with p = 23.8 and a = 5.

Answer 1

3.

$$\mu_{\bar{X}}=\mu=121.4$$

$$\sigma^2_{\bar{X}}=\sigma^2/n=50.5/25=2.02$$

$$\sigma_{\bar{X}}=\sqrt{\sigma^2_{\bar{X}}}=\sqrt{2.02}\approx1.421267$$

4.

$$\mu_{\bar{X}}=\mu=23.8$$

$$\sigma^2_{\bar{X}}=\sigma^2/n=5^2/20=1.25$$

$$\sigma_{\bar{X}}=\sqrt{\sigma^2_{\bar{X}}}=\sqrt{1.25}\approx1.118034$$