A company has been producing steel tubes of mean inner diameter of 3 cm. A sample of 17 tubes gives an inner diameter of 3.01 cm and a standard deviation of 0.064. Then the value of the t-test statistic is:

Which of the following statements are correct?

A. The measurable characteristic of a population is called parameter.

B. Sample is a subgroup of members of the population.

C. Population is a collection of all elements having the same characteristics.

D. The difference between a population parameter and a sample statistic is known as sampling error.

Choose the correct answer from the options given below:

A machine has been producing steel tubes of mean inner diameter of 2 cm. A sample of 10 tubes gives an inner diameter of 2.01 cm and a standard deviation of 0.063 cm. Test the hypothesis that the machine is working in the proper order at 5 % level of significance and answer, which of the following statements are correct?

[Given that : t₉(0.05) = 2.262]

(A) The value of the test statistic is t = 0.476.

(B) The null hypothesis is rejected at 5 % level of significance.

(C) The null hypothesis is accepted at 5 % level of significance.

(D) The degree of freedom is 10.

Choose the correct answer from the options given below:

A 95% confidence interval for a population mean was reported to be 152 to 160. If sample standard deviation $\sigma=15$, then sample size used in this study is (Given $Z_{0.025}=1.96$)

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:

Which of the following points describe the concept of population in inferential statistics ?

A. It is a collection of all elements having same characteristics.

B. A survey done on the total population is not accurate.

C. Population focuses on the identification of the characteristic.

D. Population focuses on drawing inference about the sample.

Choose the correct answer from the options given below:

A random sample of 100 individuals provides 25 positive responses.

Then the point estimate of the population proportion with "positive" responses is: