Week 7 Flashcards
What is a population in statistics
The enter group of interest in the study from which samples may be drawn
What is a sample
A smaller group selected from the population, used to make inferences about the problem
What is a parameter
A descriptive measure that characterizes a population
What is a statistic
A descriptive measure that characterizes a sample
Why do we use samples instead of entire populations
Because collecting data on the entire population is often impractical, so we use samples to estimate population characteristics
What is probability
The likelihood of an event occurring, ranging from 0 (never happening) to 1 (always happens)
What is a normal distribution
A probability distribution that is univocal and symmetrical
, often described with a mean on 0 and standard deviation of 1
How do you calculate the z score
Z= score-mean/standard deviation
What does a z score represent
It represents how many standard deviations a score is from the mean, allowing comparison across different data sets
What is a sample error
The deviation between a samples statistics and the true population parameters
What Is the law of large numbers
The principle that large sample sizes provide more accurate estimates of population characteristics
What is the central limit theorem
The theorem stating that the distribution of sample means will be approximately normal if the sample size is large enough
WHat is standard error
The standard deviation of the sample mean distribution, indicating how much the sample mean is expected to vary from the population mean
What is hypothesis testing
A method of determining if there is a statistically significant difference between a samples statistics statistic and a population parameter
What does it mean if a sample mean falls outside -1.96 to +1.96 standard errors of the population mean
It suggests a statistically significant difference, as 95% of sample means fall within this range under a normal distribution
