Which of the following are among the reasons for sampling?

1. Cost
2. Time
3. Accuracy
4. Destructive tests
5. Esthetics

I. The mean, median and mode of the t distribution are all equal to zero.

II. The t distribution is bell-shaped and symmetrical. The total area under a t-curve is 1 or  100%

III. As the degrees of freedom decreases, the shape of the t-distribution approaches to the standard normal distribution.

Which of the given statements about properties of the t-distribution are true?

Which sign we are not going to use in one sample hypothesis problems for alternate hypothesis?

In a university, a surveyor calculated the proportion of girls as 30 % and 34 % at ages 20 and 21, and proportion of boys are 26 % and 10 % of the boys at ages 20 and 21, respectively. What is the sampling method she used ?

A linguist interviews with speakers of a rare languge A. She selects a few speakerss to start with and at the end of interview he asks if the participant knows any other speakers that might want to participate. Which type of sampling method does the manager use?

Which of the following statements is false regarding the test statistic formula below, which is for two sample tests of means when their population variances are known?

A researcher wants to collect data about drug users and knows a few of them. The researcher asks identified subjects to recruit other members and this process is repeated until the determined sample size is achieved. This researcher uses _______.

Sample values for a continuous variable (noise level in a classroom ; as decibel) : 32, 38, 46, 48, 54, and 64. What is the point estimate of the population arithmetic mean?

Interval estimation : the limits of the confidence interval are (205, 245), the significance level is 0.05. What is the sample arithmetic mean?

Sample values for a continuous variable (weather temperature in a day ; as ^oC) : 10, 16, 20, and 28. What is the point estimate of the population arithmetic mean?

Which of the following problems requires a two-sided test?

Which one of the following is not a reason of sampling?

In an investigation, if the significance level is 0.47, what is the confidence level in this study?

I. If the alternative hypothesis is in the form of H₁: p1<p2 then rejection region is z<–z_?

II. If the alternative hypothesis is in the form of H₁: p1>p2 then rejection region is z>z_?

II. If the alternative hypothesis is in the form of H₁: p1?p2 then rejection region is z=z_?/2 

For the given statements about  the hypothesis test of the difference between two population proportions which ones can be said to be true?

Systematic sampling : sample size is 1024, number of members in the population is 16, random starting point is 257. Which one is the 3rd sample?

In which reason of sampling we consider "Some populations are uncountable or infinite to conduct a census"?

Which method's most important feature is efficiency?

For age variable the following sample data is gathered: 45, 47, 42, 40, and 51. What is the point estimate of the population arithmetic mean for variable age?

How many different subgroups of 5 members can be obtained from a population of 8 members?

If for 5 population groups their sum of squares between is equal to 48 and the sum of squares within is equal to 19. The total sample size of the groups is equal to 100, then what is the F test statistics?