Practice

Practise until it sticks

Choose a topic, a skill or a difficulty. Calculation exercises have new versions with fresh numbers once you have solved them, so you can practise the method rather than memorise an answer.

← Back to the list · from z-scores and relative standing

Challenge, difficulty 2 of 3

Who did relatively better?

Not started

Two sales representatives work in different regions. Aisha closed 75 deals in a region where reps average 70 deals (SD 9). Omar closed 72 deals in a region where reps average 44 deals (SD 16).

Find each rep's z-score within their own region (2 decimal places).