The correct answer is True because:
A simple random sample is a subset of a statistical population in which each member of the subset has an equal probability of being chosen. A simple random sample is meant to be an unbiased representation of a group.
In statistics, random samples are used to make generalizations, or inferences, about a population. Give a full correct answer for this question its true or false?
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Answers (1)
2020-10-19
Relevant Questions
asked 2021-02-25
Give a full and correct answer
Why is it important that a sample be random and representative when conducting hypothesis testing?
Representative Sample vs. Random Sample: An Overview
Economists and researchers seek to reduce sampling bias to near negligible levels when employing statistical analysis. Three basic characteristics in a sample reduce the chances of sampling bias and allow economists to make more confident inferences about a general population from the results obtained from the sample analysis or study:
* Such samples must be representative of the chosen population studied.
* They must be randomly chosen, meaning that each member of the larger population has an equal chance of being chosen.
* They must be large enough so as not to skew the results. The optimal size of the sample group depends on the precise degree of confidence required for making an inference.
Representative sampling and random sampling are two techniques used to help ensure data is free of bias. These sampling techniques are not mutually exclusive and, in fact, they are often used in tandem to reduce the degree of sampling error in an analysis and allow for greater confidence in making statistical inferences from the sample in regard to the larger group.
Representative Sample
A representative sample is a group or set chosen from a larger statistical population or group of factors or instances that adequately replicates the larger group according to whatever characteristic or quality is under study.
A representative sample parallels key variables and characteristics of the large society under examination. Some examples include sex, age, education level, socioeconomic status (SES), or marital status. A larger sample size reduced sampling error and increases the likelihood that the sample accurately reflects the target population.
Random Sample
A random sample is a group or set chosen from a larger population or group of factors of instances in a random manner that allows for each member of the larger group to have an equal chance of being chosen. A random sample is meant to be an unbiased representation of the larger population. It is considered a fair way to select a sample from a larger population since every member of the population has an equal chance of getting selected.
Special Considerations:
People collecting samples need to ensure that bias is minimized. Representative sampling is one of the key methods of achieving this because such samples replicate as closely as possible elements of the larger population under study. This alone, however, is not enough to make the sampling bias negligible. Combining the random sampling technique with the representative sampling method reduces bias further because no specific member of the representative population has a greater chance of selection into the sample than any other.
Summarize this article in 250 words.
asked 2020-10-18
Give full and correct answer for this question, the chi-square test can be used:
Select one:
a. to make inference about a population mean.
b. to test for survey error.
c. to compare more than two independent proportions.
d. for pairwise multiple comparisons of means.
e. to test for difference in two variances.
asked 2021-01-28
Indicate true or false for the following statements. If false, specify what change will make the statement true.
a) In the two-sample t test, the number of degrees of freedom for the test statistic increases as sample sizes increase.
b) When the means of two independent samples are used to to compare two population means, we are dealing with dependent (paired) samples.
c) The \(\displaystyle{x}^{{{2}}}\) distribution is used for making inferences about two population variances.
d) The standard normal (z) score may be used for inferences concerning population proportions.
e) The F distribution is symmetric and has a mean of 0.
f) The pooled variance estimate is used when comparing means of two populations using independent samples.
g) It is not necessary to have equal sample sizes for the paired t test.
a) In the two-sample t test, the number of degrees of freedom for the test statistic increases as sample sizes increase.
b) When the means of two independent samples are used to to compare two population means, we are dealing with dependent (paired) samples.
c) The \(\displaystyle{x}^{{{2}}}\) distribution is used for making inferences about two population variances.
d) The standard normal (z) score may be used for inferences concerning population proportions.
e) The F distribution is symmetric and has a mean of 0.
f) The pooled variance estimate is used when comparing means of two populations using independent samples.
g) It is not necessary to have equal sample sizes for the paired t test.
asked 2021-01-10
GIve a correct answer for this question: when we are comparing two population means from two groups (suppose they are called Group 1 and Group 2), which of the following statistics do we use to make a confidence interval or perform a hypothesis test for a difference in means?
asked 2021-01-06
Inference about cause and effect but can't apply those inferences to population of interest.
Which of the following best describes the statement above? Give full answer for your choice
i. designed experiment in which experimental units are randomly sampled from the population of interest
ii. designed experiment using available experimental units
iii. observational study in which samples are randomly selected from preexisting distinct groups
iv. observational study using nonrandom sample
asked 2020-11-11
Parameters and Statistics: Prove that is of Describe the population and the sample, respectively. Give a full and correct your answer for this question
asked 2021-02-11
Miutiple answers may be possible (partial credit added for correct answers, pala credit deducted for incorect answers: You can't get a negative overall score for this question):
Which ofthe following are similarities of -tests and ANOVA?
B They assume homogeneity of variances.
A) They assume the Homegeneity of variances.
B) They compare the same number of group.
C) They make inferences about the relationship between two quantitative variables
D) They compare the between to the within group variation.
E) They assume normality within groups
F) They make inferences about population means
Which ofthe following are similarities of -tests and ANOVA?
B They assume homogeneity of variances.
A) They assume the Homegeneity of variances.
B) They compare the same number of group.
C) They make inferences about the relationship between two quantitative variables
D) They compare the between to the within group variation.
E) They assume normality within groups
F) They make inferences about population means
asked 2021-02-09
A two-sample inference deals with dependent and independent inferences. In a two-sample hypothesis testing problem, underlying parameters of two different populations are compared. In a longitudinal (or follow-up) study, the same group of people is followed over time. Two samples are said to be paired when each data point in the first sample is matched and related to a unique data point in the second sample.
This problem demonstrates inference from two dependent (follow-up) samples using the data from the hypothetical study of new cases of tuberculosis (TB) before and after the vaccination was done in several geographical areas in a country in sub-Saharan Africa. Conclusion about the null hypothesis is to note the difference between samples.
The problem that demonstrates inference from two dependent samples uses hypothetical data from the TB vaccinations and the number of new cases before and after vaccination. PSK\begin{array}{|c|c|} \hline Geographical\ regions & Before\ vaccination & After\ vaccination\\ \hline 1 & 85 & 11\\ \hline 2 & 77 & 5\\ \hline 3 & 110 & 14\\ \hline 4 & 65 & 12\\ \hline 5 & 81 & 10\\\hline 6 & 70 & 7\\ \hline 7 & 74 & 8\\ \hline 8 & 84 & 11\\ \hline 9 & 90 & 9\\ \hline 10 & 95 & 8\\ \hline \end{array}ZSK
Using the Minitab statistical analysis program to enter the data and perform the analysis, complete the following: Construct a one-sided \(\displaystyle{95}\%\) confidence interval for the true difference in population means. Test the null hypothesis that the population means are identical at the 0.05 level of significance.
This problem demonstrates inference from two dependent (follow-up) samples using the data from the hypothetical study of new cases of tuberculosis (TB) before and after the vaccination was done in several geographical areas in a country in sub-Saharan Africa. Conclusion about the null hypothesis is to note the difference between samples.
The problem that demonstrates inference from two dependent samples uses hypothetical data from the TB vaccinations and the number of new cases before and after vaccination. PSK\begin{array}{|c|c|} \hline Geographical\ regions & Before\ vaccination & After\ vaccination\\ \hline 1 & 85 & 11\\ \hline 2 & 77 & 5\\ \hline 3 & 110 & 14\\ \hline 4 & 65 & 12\\ \hline 5 & 81 & 10\\\hline 6 & 70 & 7\\ \hline 7 & 74 & 8\\ \hline 8 & 84 & 11\\ \hline 9 & 90 & 9\\ \hline 10 & 95 & 8\\ \hline \end{array}ZSK
Using the Minitab statistical analysis program to enter the data and perform the analysis, complete the following: Construct a one-sided \(\displaystyle{95}\%\) confidence interval for the true difference in population means. Test the null hypothesis that the population means are identical at the 0.05 level of significance.
asked 2021-01-05
Give full and correct answer for this questions 1) A t-test is a ?
2) Which of the following statement is true?
a)The less likely one is to commit a type I error, the more likely one is to commit a type II error,
b) A type I error has occurred when a false null hypothesis has been wrongly accepted.
c) A type I error has occurred when a two-tailed test has been performed instead of a one-tailed test,
d) None of the above statements is true.
3)Regarding the Central Limit Theorem, which of the following statement is NOT true?
a.The mean of the population of sample means taken from a population is equal to the mean of the original population.
b. The frequency distribution of the population of sample means taken from a population that is not normally distributed will approach normality as the sample size increases.
c. The standard deviation of the population of sample means is equal to the standard deviation of the, original population.
d. The frequency distribution of the population of sample means taken from a population that is not normally distributed will show less dispersion as the sample size increases.
asked 2020-12-28
Is statistical inference intuitive to babies? In other words, are babies able to generalize from sample to population? In this study,1 8-month-old infants watched someone draw a sample of five balls from an opaque box. Each sample consisted of four balls of one color (red or white) and one ball of the other color. After observing the sample, the side of the box was lifted so the infants could see all of the balls inside (the population). Some boxes had an “expected” population, with balls in the same color proportions as the sample, while other boxes had an “unexpected” population, with balls in the opposite color proportion from the sample. Babies looked at the unexpected populations for an average of 9.9 seconds (sd = 4.5 seconds) and the expected populations for an average of 7.5 seconds (sd = 4.2 seconds). The sample size in each group was 20, and you may assume the data in each group are reasonably normally distributed. Is this convincing evidence that babies look longer at the unexpected population, suggesting that they make inferences about the population from the sample?
Let group 1 and group 2 be the time spent looking at the unexpected and expected populations, respectively.
A) Calculate the relevant sample statistic.
Enter the exact answer.
Sample statistic: _____
B) Calculate the t-statistic.
Round your answer to two decimal places.
t-statistic = ___________
C) Find the p-value.
Round your answer to three decimal places.
p-value =
