Define mean in statistics.
The average value of a set of numbers, calculated by dividing the sum by the count.
True or false: The median is always the middle value in a dataset.
TRUE
The median is the value separating the higher half from the lower half of the dataset.
What does standard deviation measure?
It measures the amount of variation or dispersion in a set of values.
Fill in the blank: The mode is the value that appears ______ most frequently.
most
Define variance.
The average of the squared differences from the mean, indicating data spread.
What is a sample in statistics?
A subset of a population used to represent the whole population.
True or false: A population includes all members of a defined group.
TRUE
What is hypothesis testing?
A method to determine if there is enough evidence to reject a null hypothesis.
Fill in the blank: A p-value indicates the probability of observing results ______ the null hypothesis.
if
Define confidence interval.
A range of values derived from a sample that is likely to contain the population parameter.
What is a normal distribution?
A probability distribution that is symmetric about the mean, forming a bell curve.
True or false: In a skewed distribution, data is symmetrically distributed around the mean.
FALSE
Skewed distributions have a longer tail on one side.
What does correlation measure?
The strength and direction of a linear relationship between two variables.
Fill in the blank: Regression analysis is used to predict the value of one variable based on ______.
another variable
Define outlier.
A data point that differs significantly from other observations in a dataset.
What is a box plot?
A graphical representation of data that shows the distribution’s quartiles and outliers.
True or false: A scatter plot shows the relationship between two quantitative variables.
TRUE
What is descriptive statistics?
Statistics that summarize or describe characteristics of a dataset.
Fill in the blank: Inferential statistics allows us to make predictions about a population based on a ______.
sample
Define type I error.
The incorrect rejection of a true null hypothesis, also known as a false positive.
What is data normalization?
The process of adjusting values in a dataset to a common scale.
True or false: A bar chart is used to compare categorical data.
TRUE
What is a frequency distribution?
A summary of how often each value occurs in a dataset.
Fill in the blank: The interquartile range measures the spread of the middle ______ of data.
50%
