Statistics Quest

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.

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Challenge, difficulty 3 of 3

Correcting for nonresponse

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The engagement survey over-represents the more engaged departments. Estimate the mean answer to q6_intend_stay (“I intend to be working here in 12 months' time”, 1–5) for all employees by weighting:

  1. compute the mean of q6_intend_stay in each department (ignore skipped answers);
  2. weight each department mean by the department's headcount:
DepartmentHeadcount
Operations420
Customer Service330
Sales260
Technology210
Finance120
Human Resources60

Give the weighted mean to 2 decimal places. (Treating the 1–5 codes as numbers is a simplification commonly used for tracking.)

Data: engagement_survey · Open in the lab to explore and calculate.