Endgames Statistical Question

Describing the spread of data I

BMJ 2010; 340 doi: https://doi.org/10.1136/bmj.c1116 (Published 04 March 2010) Cite this as: BMJ 2010;340:c1116
  1. Philip Sedgwick, senior lecturer in medical statistics
  1. 1Centre for Medical and Healthcare Education, St George’s, University of London, London SW17 0RE
  1. p.sedgwick{at}sgul.ac.uk

    Using a prospective cohort study design, researchers investigated the relation between slow walking speed and risk of death in older people.1 A sample of 3208 French men and women aged over 65 years living in the community were recruited in 1999. At baseline the sample had a mean age of 73.2 years with a standard deviation of 4.6 years.

    Which of the following, if any, are true?

    • a) The mean age of the sample is a point estimate of the mean age of the population

    • b) The sample standard deviation is a measure of the spread of …

    View Full Text

    Sign in

    Log in through your institution

    Free trial

    Register for a free trial to thebmj.com to receive unlimited access to all content on thebmj.com for 14 days.
    Sign up for a free trial

    Subscribe