举一反三
- A researcher wants to estimate the difference in the means of two populations. A random sample of 36 items from the first population results in a sample mean of 430. A random sample of 49 items from t
- which statement is right? A: We can observe the entire population. B: A sample drawn from the population of interest. is not adequate to discribe population. C: In the Monte Carlo demonstration from last time, an individual dataset was the sample and the Data Generating Process described the population. D: none of the above is right
- A sample in which the characteristics of the sample are the same as those of the population is a(n): （ ） A: attributes sample. B: variables sample. C: random sample. D: representative sample.
- A sample of 400 observations will be taken from an infinite population. The population proportion equals 0.8. The probability that the sample proportion will be greater than 0.83 is
- A researcher wants to estimate the proportion of the population which possess a given characteristic. A random sample of size 600 is taken resulting in 330 items which possess the characteristic. The point estimate for this population proportion is _______.
内容
- 0
A researcher is interested in testing to determine if the mean of population one is greater than the mean of population two. The null hypothesis is that there is no difference in the population means (i.e. the difference is zero). The alternative hypothesis is that there is a difference (i.e. the difference is not equal to zero). He randomly selects a sample of 9 items from population one resulting in a mean of 14.3 and a standard deviation of 3.4. He randomly selects a sample of 14 items from population two resulting in a mean of 11.8 and a standard deviation 2.9. He is using an alpha value of .10 to conduct this test. Assuming that the populations are normally distributed, the critical t-value from the table is _______.
- 1
A<br/>sample in which the characteristics of the sample are the same as<br/>those of the population is a ( ) A: variables<br/>sample. B: representative<br/>sample. C: attributes<br/>sample. D: random<br/>sample.
- 2
The study is restricted by some limitation. ______, the population of the study included a sample from only one city, whereas other cities have not been tackled. ________, the study utilizes one instrument, mainly a questionnaire, while other instruments such as in-depth interviews and observation were not used.
- 3
Which of the following is NOT a reason for the need for sampling? A: It is usually too costly to study the whole population. B: It is usually too time consuming to look at the whole population. C: It is sometimes destructive to observe the entire population. D: It is always more informative by investigating a sample than the entire population.
- 4
A summary measure that is computed from a sample to describe a characteristic of the population is called: