APCSP Data and Analysis 2 — Questions and Answers
Question 1: A dataset contains the ages of 1,000 survey respondents. Which measure of center is MOST affected by a few extremely old respondents?
- Median
- Mode
- Mean (Correct answer)
- Midrange of median values
Correct answer: Mean
The mean is sensitive to outliers because it incorporates every value in the calculation, so extreme values pull it significantly.
Question 2: Which file format stores data as plain text with values separated by commas and is widely used for exchanging tabular data?
- JSON
- XML
- CSV (Correct answer)
- HTML
Correct answer: CSV
CSV (Comma-Separated Values) stores tabular data as plain text with commas delimiting fields, making it universally readable.
Question 3: A program filters a list of temperatures, keeping only values above 100°F. After filtering 500 readings, only 3 remain. What is the BEST description of those 3 values?
- Representative samples
- Outliers (Correct answer)
- The median values
- Normalized data
Correct answer: Outliers
Values that fall far outside the typical range of a dataset are called outliers, and here only 3 of 500 readings exceeded 100°F.
Question 4: Which of the following BEST describes lossy data compression?
- Data is compressed with no information lost
- The original data can be perfectly reconstructed
- Some data is permanently discarded to reduce file size (Correct answer)
- Data is encrypted before being stored
Correct answer: Some data is permanently discarded to reduce file size
Lossy compression permanently removes some data to achieve smaller file sizes, meaning the original cannot be perfectly reconstructed.
Question 5: A researcher collects data on ice cream sales and drowning incidents and finds a strong positive correlation. What is the MOST reasonable conclusion?
- Ice cream causes drowning
- A third variable (hot weather) likely explains both (Correct answer)
- Drowning causes ice cream sales to rise
- The correlation is meaningless and should be ignored
Correct answer: A third variable (hot weather) likely explains both
Correlation does not imply causation; hot summer weather is a confounding variable that increases both ice cream sales and swimming (and thus drowning risk).
Question 6: In a spreadsheet, a column labeled 'ZIP Code' contains values like 07001. If the program treats this column as a number and drops the leading zero, what type of problem has occurred?
- Overflow error
- Data type mismatch causing data loss (Correct answer)
- Rounding error
- Metadata corruption
Correct answer: Data type mismatch causing data loss
Treating ZIP codes (which are identifiers, not quantities) as numeric data types causes leading zeros to be dropped, losing meaningful information.
Question 7: Which of the following is an example of metadata?
- The pixels of a photo
- The audio waveform in an MP3 file
- The date a photo was taken and the camera model used (Correct answer)
- The lyrics stored inside a music file
Correct answer: The date a photo was taken and the camera model used
Metadata is data about data — the date taken and camera model describe the photo without being part of the image content itself.
APCSP Data and Analysis 2
A dataset contains the ages of 1,000 survey respondents.
Which measure of center is MOST affected by a few extremely old respondents?