Questions: Each of the following normal quantile plots illustrates a sample. In which cases is it reasonable to treat this as a sample from an approximately normal population? (More than one graph may be selected.)
Transcript text: Each of the following normal quantile plots illustrates a sample. In which cases is it reasonable to treat this as a sample from an approximately normal population? (More than one graph may be selected.)
Solution
Solution Steps
Step 1: Identify the purpose of the normal quantile plots
The purpose of normal quantile plots (Q-Q plots) is to determine if a data set is approximately normally distributed. If the points in the plot lie approximately along a straight line, the data can be considered to come from a normal distribution.
Step 2: Analyze each plot for linearity
Top-left plot: The points deviate significantly from a straight line, especially at the tails. This suggests the data is not normally distributed.
Top-right plot: The points lie approximately along a straight line, indicating the data is likely normally distributed.
Bottom-left plot: The points lie approximately along a straight line, indicating the data is likely normally distributed.
Bottom-right plot: The points lie approximately along a straight line, indicating the data is likely normally distributed.
Step 3: Determine which plots indicate normality
Based on the analysis:
Top-right plot: Reasonable to treat as a sample from an approximately normal population.
Bottom-left plot: Reasonable to treat as a sample from an approximately normal population.
Bottom-right plot: Reasonable to treat as a sample from an approximately normal population.
Final Answer
The plots that illustrate samples that can be reasonably treated as from an approximately normal population are: