Đề 4 – Bài tập, đề thi trắc nghiệm online Thống kê trong kinh tế và kinh doanh

A A. It is when the dependent variable is correlated with itself over time; it's a problem because it violates assumptions of time series analysis. B B. It is high correlation among independent variables; it's a problem because it makes it difficult to isolate the individual effect of each independent variable. C C. It is when residuals are not normally distributed; it's a problem because it invalidates hypothesis tests. D D. It is when the variance of errors is not constant across observations; it's a problem because it leads to inefficient estimators.

A A. A long-term upward or downward movement in data. B B. Irregular fluctuations in data. C C. A pattern that repeats at regular intervals over time, typically within a year. D D. Random variations in data.

A A. Symmetric around the mean. B B. Unimodal (has one mode). C C. Skewed to the right. D D. Defined by two parameters: mean and standard deviation.

A A. To make the analysis process longer and more complex. B B. To ensure the test results are valid and reliable. C C. Because all statistical software requires assumption checking. D D. To increase the p-value and reject the null hypothesis more easily.

A A. A random error that occurs in every sample. B B. A systematic error that leads to a sample not representative of the population. C C. The difference between the sample mean and the population mean. D D. The size of the sample relative to the population.

A A. Causation between the two variables. B B. A strong linear relationship between the two variables. C C. No relationship between the two variables. D D. A non-linear relationship between the two variables.

A A. Short-term fluctuations in data. B B. Regular seasonal patterns. C C. Long-term direction or movement in data. D D. Random noise in data.

A A. Describing economic phenomena and business conditions. B B. Predicting future economic trends and business outcomes. C C. Controlling political elections. D D. Making informed decisions under uncertainty.

A A. Nominal data B B. Ordinal data C C. Interval data D D. Ratio data

A A. To determine the exact value of a population parameter. B B. To provide a range of plausible values for a population parameter. C C. To test hypotheses about population parameters. D D. To eliminate sampling error.

A A. Mean B B. Median C C. Standard Deviation D D. Mode

A A. To compare the means of two independent groups. B B. To compare the means of three or more groups. C C. To analyze the correlation between two variables. D D. To predict the value of a dependent variable.

A A. Median B B. Mode C C. Mean D D. Geometric Mean

A A. Normal distribution B B. Binomial distribution C C. Poisson distribution D D. Exponential distribution

A A. T-test B B. ANOVA C C. Chi-squared test D D. Regression analysis

A A. Correlation analysis B B. Regression analysis C C. Independent samples t-test D D. Chi-squared test

A A. The most recent period in the data. B B. A reference period against which changes are measured. C C. The period with the highest value in the data. D D. The period with the lowest value in the data.

A A. A population is always larger than a sample. B B. A sample is a subset of the population. C C. A population is used for descriptive statistics, while a sample is for inferential statistics. D D. All of the above.

A A. The researcher's belief about the population. B B. The alternative hypothesis. C C. A statement of no effect or no difference. D D. A statement that is always true.

A A. To select samples randomly without any specific structure. B B. To divide the population into subgroups (strata) and then randomly sample from each stratum. C C. To sample every nth member of the population. D D. To select samples based on convenience.

A A. Pie chart B B. Bar chart C C. Histogram D D. Scatter plot

A A. The mean of any sample is always equal to the population mean. B B. The standard deviation of the sample mean is equal to the population standard deviation. C C. For a sufficiently large sample size, the distribution of sample means will be approximately normal, regardless of the population's distribution. D D. The sample median is always a better estimator of central tendency than the sample mean.

A A. Customer ages at a single point in time. B B. Sales revenue recorded quarterly for the past five years. C C. Survey responses from a one-time survey. D D. Cross-sectional data of company profits in a single year.

A A. Type I error is rejecting a false null hypothesis; Type II error is failing to reject a true null hypothesis. B B. Type I error is failing to reject a false null hypothesis; Type II error is rejecting a true null hypothesis. C C. Type I error is rejecting a true null hypothesis; Type II error is failing to reject a false null hypothesis. D D. Type I and Type II errors are the same thing but referred to differently in different fields.

A A. Non-linear relationship between variables. B B. Correlation between independent variables. C C. Unequal variance of errors across different levels of independent variables. D D. Non-normality of residuals.

A A. It represents the probability that the null hypothesis is true. B B. It is the significance level chosen before conducting the test. C C. It measures the strength of the alternative hypothesis. D D. It is the probability of observing the data (or more extreme data) if the null hypothesis is true.

A A. To perform complex statistical calculations. B B. To make data more understandable and identify patterns. C C. To replace statistical analysis entirely. D D. To store large datasets.

A A. The statistical significance of the independent variables. B B. The strength and direction of the relationship between variables. C C. The proportion of variance in the dependent variable that is predictable from the independent variables. D D. The probability of rejecting the null hypothesis.

A A. To summarize data with charts and graphs. B B. To describe the distribution of a single variable. C C. To model the relationship between a dependent variable and one or more independent variables. D D. To calculate probabilities of events.

A A. To prove the alternative hypothesis is true. B B. To indicate the practical importance of the findings. C C. To provide evidence against the null hypothesis. D D. To ensure the sample is representative of the population.