Tamanna was researching on problem of under-age workers at factories. She met a suitable child and interviewed him. He put her in contact with three another workers. Those three workers brought her in contact with ten other underage workers. This process of sampling is known as:

If n is the sample size of the population, then degree of freedom in t-distribution is

A sample of 100 LED TVs is taken at random. Out of 100 we found 35 TVs are of Sony, 50 are of LG and 15 are of Samsung. The point estimate of population proportion of LG is

Consider the following hypothesis test:

$H_0: \mu \leq 12$

$H_a: \mu > 12$

A sample of 25 provided a sample mean $\bar{x} = 14$ and a sample standard deviation $s = 4.32$. If $t_{0.05} = 1.711$, then which of the following is correct?

(A) The test statistic is defined as $t = \frac{\bar{x} - \mu}{\frac{s}{\sqrt{n}}}$.

(B) The value of the test statistic is 1.31.

(C) At $\alpha = 0.05$, the null hypothesis is rejected.

(D) If the value of the t-statistic is less than $t_\alpha$, then null hypothesis is accepted.

Choose the correct answer from the options given below:

The following data is from a simple random sample :

$15,23, x, 37,19,32$

If the point estimate of the population mean is $23$, then the value of $x$ is :

Which one of the following statement is not correct?

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 $\mathrm{Z}_{0.025}=1.96$ )