Daily Practice

Foundation

25th February 2025

5 questions · Foundation tier · 282 questions in this band

1
Data Cleaning and Outliers (Foundation)
A data set of ages is: 12, 13, 12, 14, 13, 99. Which value is most likely an outlier?
2
Correlation and Causation (Foundation)
Two variables have a correlation coefficient close to 0. What does this suggest?
3
Risk (Foundation)
Using your answers to the previous question, find the relative risk for phone users compared with non-users, and interpret it.
4
Skewness by Inspection
A shop's till receipts have mode 5 pounds, median 8 pounds, mean 15 pounds. State the type of skew and give a reason.
5
Percentiles
In a data set of 200 values, at what position, counting from the smallest, would you expect to find the 25th percentile?

You are looking at an earlier sheet. Today's sheet is the one that adds a day.

Your run is kept in this browser only, and there is no account.

Any date always gives the same five questions, so a sheet can be set again or shared. All of February 2025, including the monthly compilation PDF.