#1
What is sampling in statistics?
The process of selecting a subset of individuals from a population
ExplanationSelecting subset from a population.
#2
What is the purpose of statistical inference?
To make predictions or inferences about a population based on sample data
ExplanationMaking predictions from sample data.
#3
What is the purpose of a hypothesis test in statistics?
To determine if there is a significant difference between two or more groups
ExplanationDetermining significant differences between groups.
#4
Which of the following is NOT a measure of central tendency?
Variance
ExplanationNot a measure of central tendency.
#5
Which of the following sampling methods is based on random selection and ensures each member of the population has an equal chance of being chosen?
Simple random sampling
ExplanationRandom selection with equal chances.
#6
What is the standard error of the mean?
The standard deviation of the sampling distribution of the sample mean
ExplanationStandard deviation of sample mean distribution.
#7
What is the purpose of a confidence interval in statistics?
To estimate the range within which the population parameter is likely to fall
ExplanationEstimating population parameter range.
#8
Which of the following is NOT a requirement for conducting a hypothesis test?
Equal variances of samples
ExplanationNot requiring equal sample variances.
#9
Which statistical test is appropriate for comparing the means of two independent groups?
Independent samples t-test
ExplanationComparing means of independent groups.
#10
What is stratified sampling?
A sampling method where the population is divided into groups and a random sample is taken from each group
ExplanationRandom sampling from population groups.
#11
Which of the following statements is true about Type I error?
Type I error occurs when the null hypothesis is incorrectly rejected
ExplanationIncorrectly rejecting null hypothesis.
#12
In statistical inference, what does a p-value represent?
The probability of observing the sample data or more extreme data, given that the null hypothesis is true
ExplanationProbability of observing data given null hypothesis.
#13
Which of the following statements about Type I and Type II errors is correct?
Type I error occurs when the null hypothesis is incorrectly rejected
ExplanationIncorrectly rejecting null hypothesis.
#14
What is the central limit theorem?
A theorem stating that the mean of a sufficiently large sample follows a normal distribution, regardless of the population distribution
ExplanationMean of large sample follows normal distribution.
#15
What is the formula for calculating the margin of error in a confidence interval?
z * (standard deviation / square root of sample size)
ExplanationFormula for margin of error calculation.
#16
What is the formula for the standard error of the mean (SEM)?
Standard deviation / square root of sample size
ExplanationFormula for SEM calculation.
#17
Which of the following statements about the t-distribution is correct?
The t-distribution has fatter tails than the standard normal distribution
ExplanationFatter tails than normal distribution.
#18
What is the purpose of a Type II error in hypothesis testing?
To incorrectly fail to reject the null hypothesis when it is false
ExplanationIncorrectly retaining null hypothesis when false.