Lecture 12 Flashcards
When could bias influence sampling?
Bias could influence sampling when the selection process is not random or when certain groups are overrepresented or underrepresented.
How can you recognize a normal curve?
A normal curve is a symmetric, bell-shaped curve centered around the mean.
When is a sampling distribution expected to follow a normal bell-shaped curve?
A sampling distribution follows a normal bell-shaped curve when the sample size is large enough, typically due to the Central Limit Theorem.
How does the spread of the sampling distribution change with sample size?
The spread of the sampling distribution decreases as the sample size increases.
What describes the sampling distribution for comparing two groups?
The sampling distribution for comparing two groups is centered on the difference between their population means and its spread is determined by the standard errors of the two samples.
What are the key characteristics used to describe the distributions of population, sample, and sampling distribution?
Population is described by mean and standard deviation, sample by sample mean and sample standard deviation, and sampling distribution by the population mean (if unbiased) and standard error.
What is the standard error?
The standard error is the standard deviation of the sampling distribution.
What information is needed to draw the shape of a normal distribution?
The mean and standard deviation are needed to draw the shape of a normal distribution.
What is the equation of a regression line?
The equation of a regression line is y = a + b × x, where a is the intercept, b is the slope, and x is the variable.
