Apply probability Apply probability methods, using methods, using Apply relational extended abstract probability thinking, in thinking, in solving methods in solving problems. problems. solving problems. [ 0.654] Correct 2a(i) probability calculated. [ 0.332] Correct probability 2a(ii) calculated. [ 0.545] = 54.5% Correct 2a(iii) percentage calculated. = 1336 (or 1337) Correct Expected 2a(iv) probability number calculated. calculated. Using GONE: 0.668 have improved 2a(v) dandruff. Comparison Correct conclusion Using OFF : 0.635 have improved made between AND supported by dandruff. GONE and calculations. I use GONE as the chance of improved OFF. dandruff is slightly greater. OR There is very little difference in the two results and it may depend on the price or aroma as to my choice. 2b(i) Correct table or Correct numbers probability calculated. calculated. Prob required = 0.843 2b(ii) Prob (dandruff of a male’s dandruff improving A correct Both correct Probabilities using GONE) = 0.783 probability probabilities correctly compared Prob (dandruff of a male’s dandruff improving calculated. calculated. and a justified OFF) = 0.4 statement made. So relative risk of dandruff improving using GONE is 1.96 so company claim is close to being correct. However sample using OFF was very small and may have been misleading and possibly changed a lot with a bigger sample. Perhaps further study with a larger should be undertaken before results used.
Apply probability methods in solving problems. Apply probability methods, using relational thinking, in solving problems. Apply probability methods, using extended abstract thinking, in solving problems. 2a(i) [ 0.654] Correct probability calculated. 2a(ii) [ 0.332] Correct probability calculated. 2a(iii) [ 0.545] = 54.5% Correct percentage calculated. 2a(iv) = 1336 (or 1337) Correct probability calculated. Expected number calculated. 2a(v) Using GONE: 0.668 have improved dandruff. Using OFF : 0.635 have improved dandruff. I use GONE as the chance of improved dandruff is slightly greater. OR There is very little difference in the two results and it may depend on the price or aroma as to my choice. Comparison made between GONE and OFF. Correct conclusion AND supported by calculations. 2b(i) Prob required = 0.843 Correct table or numbers calculated. Correct probability calculated. 2b(ii) Prob (dandruff of a male’s dandruff improving using GONE) = 0.783 Prob (dandruff of a male’s dandruff improving OFF) = 0.4 So relative risk of dandruff improving using GONE is 1.96 so company claim is close to being correct. However sample using OFF was very small and may have been misleading and possibly changed a lot with a bigger sample. Perhaps further study with a larger should be undertaken before results used. A correct probability calculated. Both correct probabilities calculated. Probabilities correctly compared and a justified statement made.
2012_eoy_level_2_probability_exam.docx