Match List-I with List-II

List-I	List-II
(A) It describes the accuracy of a sampling method.	(I) Confidence interval
(B) It describes the uncertainity of a sampling method.	(II) Hypothesis
(C) It is used to express the precision and uncertainity of a sampling process.	(III) Margin of error
(D) An educated guess which needs to be tested.	(IV) Confidence level

Choose the correct answer from the options given below:

Let us suppose that two independent random samples of sizes $n_1$ and $n_2$ has been drawn from the same normal population then degree of freedom of statistic t-distribution is:

If $x_1, x_2, x_3, ..., x_n$ are n observations in a sample then which of following is/are TRUE?

(A) The mean $\bar{x}$ has n degree of freedom

(B) The mean $\bar{x}$ has (n-1) degree of freedom

(C) The standard deviation of the sample has (n-1) degree of freedom

(D) The standard deviation of the sample has n degree of freedom

Choose the correct answer from the options given below:

Which of the following are correct?

(A) The probability curve in t-distribution is symmetric about the line t=0.

(B) t-axis is an asymptote of the curve.

(C) The variable t of t-distribution ranges from $-\infty$ to $\infty$

(D) As the number of degrees of freedom increases, the t-distribution curve moves closer to the binomial distribution.

Choose the correct answer from the options given below:

If $95 \%$ confidence interval for the population mean was reported to be $160$ to $170$ and $\sigma=25$, then size of the sample used in this study is: (Given $\mathrm{Z}_{0.025}=1.96$ )

If 95% confidence interval for the population mean was reported to be 140 to 150 and $\sigma = 25$, then size of the sample used in this study is:

[Given: $Z_{0.025} = 1.96$]

The monthly salaries of workers in a garment factory are normally distributed. The mean salary is ₹ 10,000 and standard deviation is ₹ 625. If 2,500 workers are getting salary less than ₹ 10,000, then the total number of workers in the factory is: