Statistical Inference

Question 1

What is a random sample

Answer 1

a subset of individuals chosen from a population where each member has an equal chance of being selected
helps avoid bias and ensures the sample represents the population

Question 2

What is a sample of convenience

Answer 2

taken from a group that is easy to access or contact, rather than randomly selected
faster and cheaper but can lead to bias

Question 3

What is a sampling error

Answer 3

the difference between a sample statistic and the actual population parameter, happens by chance.

Question 4

What is bias

Answer 4

a systematic error that skews results in a particular direction

Question 5

What is precision

Answer 5

how consistent repeated measurements are (low variability)

Question 6

What is accuracy

Answer 6

how close a measurement is to the true value

Question 7

What is frequency distribution

Answer 7

a graph or table showing how often each value in a dataset occurs

Question 8

What is probability density function

Answer 8

a function that describes the likelihood of a continuous random variable falling within a range of values

Question 9

What are the main measures of central tendency

Answer 9

Mean (average)
Median (middle value)
Mode (most frequent value)

Question 10

What is a sampling distribution

Answer 10

the probability distribution of a statistic (like the mean) based on all possible random samples from a population.