Estimation Quiz 5

1. For a normal population with known population standard deviations $\sigma_1$ and $\sigma_2$ ,the confidence interval estimate for the difference between two population mean $(\mu_1-\mu_2)$ is

2. For a large sample, the confidence interval estimate for the difference between two population proportions $p_1-p_2$ is

3. In the case of paired observations (for a small sample $n\le 30$), the confidence interval estimate for the difference of two population means $\mu_1-\mu_2=\mu_d$ is

4. The following statistics are unbiased estimators

5. If t-distribution for two independent sample $n_1=n_2=n$, then the degrees of freedom will be

6. Which one of the following is a biased estimator?

7. Suppose the 90% confidence Interval for population mean $\mu$ is -24.3 cents to 64.3 cents, the sample mean $\overline{X}$ is

8. If $1-\alpha=0.90$ then value of $Z_{\frac{\alpha}{2}}$ is

9. If the population standard deviation $\sigma$ is unknown and the sample size $n$ is less than or equal to 30, the confidence interval for the population mean $\mu$ is

10. If the population standard deviation ($\sigma$) is known and the sample size ($n$) is less than or equal to or more than 30, the confidenc interval for the population mean ($\mu$) will be

11. A 95% confidence interval for population proportion is 32.4% to 47.6%, the value of the sample proportion $\hat{p}$ is

12. For $n$ paired number of observations, the degrees of freedom for Paired Sample t-test will be

13. If $n_1, n_2\le 30$ the confidence interval estimate for the difference of two population means ($\mu_1-\mu_2$) when population standard deviations $\sigma_1, \sigma_2$ are unknown but equal in case of pooled variates is:

14. A statistic is an unbiased estimator of a parameter if:

15. If the population standard deviation ($\sigma$) is unknown and the sample size ($n$) is greater than 30, the confidence interval for the population mean $\mu$ is