Plan to spend about 1 hour on the following exercises

  1. Test if coin is fair using exact test, normal approximation and LRT. The data are
    1. number of tosses is 100 and number of heads is 40
    2. number of tosses is 1000 and number of heads is 460
  2. Consider a SNP with variants, A and T. In an association analysis experiment, the following data were obtained: 27 subjects had genotype AA, 219 subjects had genotype AT and 414 subjects had genotype TT. Question: what is the frequency of A allele? Do the genotypic frequencies follow Hardy-Weinberg distribution? answer
  3. Consider a SNP with variants, A and T. In an association analysis experiment, the following data were obtained: 131 subjects had genotype AA, 335 subjects had genotype AT and 377 subjects had genotype TT. Question: what is the frequency of A allele? Do the genotypic frequencies follow Hardy-Weinberg distribution? answer
  4. First, use chi-squared test to see if the described samples are in HWE. Second, use exact test for HWE (available at http://ihg.gsf.de/cgi-bin/hw/hwa1.pl). Compare results from chi2 and exact test. Is there much difference? If yes, how can you explain it?
    Data are given for DD, DN and NN genotypes:
    1. 2 : 17 : 81
    2. 6 : 29 : 71
    3. 3 : 16 : 81
    4. 1 : 4 : 95
  5. In a population, average inbreeding coefficient is 1/16. Frequency of an allele is 0.1. Assuming that your data exactly follow the model, try to figure out if it is pheasible to detect deviation from HWE due to inbreeding on a sample of size of
    1. 100
    2. 1,000
    3. 10,000