Data
What is the term for the data point that occurs most frequently in a dataset?
Mode
What does a Z-score indicate?
The number of standard deviations a data point is from the mean.
What is the mean of the numbers 3, 4, 5?
4
What graph shows frequency of data as bars?
Histogram
What defines a random sample?
Every member of the population has an equal chance of being selected.
What is the range of a dataset?
The difference between the maximum and minimum values.
What is the Z-score of a mean value?
Zero.
What is the median in a sorted set 1, 3, 3, 6, 7?
3
What is the purpose of a scatter plot?
To show relationship or correlation between variables.
What is a simple random sample?
Every member has an equal and independent chance.
What is an outlier in a data set?
A data point significantly different from others.
How is a Z-score calculated?
Z = (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.
How is the weighted mean different from the arithmetic mean?
It accounts for varying degrees of importance for data points.
How does a histogram differ from a bar chart?
A histogram represents continuous data, whereas a bar chart shows categorical data.
What is the purpose of random assignment in experiments?
To ensure treatment effects are free from bias.
How do you compute the interquartile range (IQR)?
IQR = Q3 - Q1, where Q3 is the third quartile and Q1 the first.
What does a Z-score of 2 tell you about data point's position?
The data point is 2 standard deviations above the mean.
Find the mean of 2, 5, 7, 9, x if x is 11
6.8
What is the main feature of a normal distribution curve's shape?
Symmetrical and bell-shaped with mean, median, mode at center.
Define systematic sampling method.
Selecting every nth member from a list.
What is a box plot, and what does it represent in a dataset?
A graphical representation using a box and whiskers to show the spread and central tendency.
Why are Z-scores used in standardizing data?
They allow comparison of data across different scales or distributions.
How does skewness affect mean and median?
If skewed right, mean > median; if left, mean < median.
What are the 5 important components in a box N whisker plot?
Median, Q1, Q3, Min, Max
Explain the difference between random sampling and random assignment.
Random sampling is for selecting participants; random assignment allocates them to groups.