BESC STAT POST TEST CH 5
QUESTIONS AND ANSWERS | LATEST
VERSION | GRADED A+
Why is random assignment important in experiments?
✔✔Random assignment reduces bias by ensuring each participant has an equal chance of being
assigned to any group, improving validity of results.
What does the central limit theorem state?
✔✔The central limit theorem states that the distribution of sample means approaches a normal
distribution as the sample size increases, regardless of the population's shape.
What is statistical inference?
✔✔Statistical inference involves making conclusions about a population based on sample data,
often using estimates and hypothesis testing.
What is a confidence level, and what does it indicate?
✔✔A confidence level indicates the degree of certainty that a confidence interval contains the
population parameter, commonly set at 95% or 99%.
1
, How does increasing the sample size affect the margin of error?
✔✔Increasing the sample size reduces the margin of error, making estimates more precise and
reliable.
What is the primary purpose of regression analysis?
✔✔Regression analysis examines relationships between variables to make predictions about a
dependent variable based on one or more independent variables.
What does it mean for results to be statistically significant?
✔✔Statistically significant results indicate that the observed effect is unlikely to be due to
chance, suggesting a real difference or relationship exists.
What is the law of large numbers?
✔✔The law of large numbers states that as sample size increases, the sample mean approaches
the population mean, improving estimate accuracy.
What is meant by variability in a dataset?
✔✔Variability refers to how spread out data points are, showing the diversity or dispersion
within a dataset.
2
QUESTIONS AND ANSWERS | LATEST
VERSION | GRADED A+
Why is random assignment important in experiments?
✔✔Random assignment reduces bias by ensuring each participant has an equal chance of being
assigned to any group, improving validity of results.
What does the central limit theorem state?
✔✔The central limit theorem states that the distribution of sample means approaches a normal
distribution as the sample size increases, regardless of the population's shape.
What is statistical inference?
✔✔Statistical inference involves making conclusions about a population based on sample data,
often using estimates and hypothesis testing.
What is a confidence level, and what does it indicate?
✔✔A confidence level indicates the degree of certainty that a confidence interval contains the
population parameter, commonly set at 95% or 99%.
1
, How does increasing the sample size affect the margin of error?
✔✔Increasing the sample size reduces the margin of error, making estimates more precise and
reliable.
What is the primary purpose of regression analysis?
✔✔Regression analysis examines relationships between variables to make predictions about a
dependent variable based on one or more independent variables.
What does it mean for results to be statistically significant?
✔✔Statistically significant results indicate that the observed effect is unlikely to be due to
chance, suggesting a real difference or relationship exists.
What is the law of large numbers?
✔✔The law of large numbers states that as sample size increases, the sample mean approaches
the population mean, improving estimate accuracy.
What is meant by variability in a dataset?
✔✔Variability refers to how spread out data points are, showing the diversity or dispersion
within a dataset.
2
