Question

Question 2 (a) Service engineers in an office building are checking reports that the heating system is not working properly, and that the temperatures of different parts of the building are different. Sample temperature measurements (in degrees Celsius) on two floors are as follows: Floor 2 19.9 20.7 22.0 18.2 23.3 21.2 22.2 21.2 Floor 6 17.7 19.6 18.9 21.3 20.9 20.3 17.5 18.8 22.8 20.6 18.2 19.9 The sample variance of the floor 2 temperatures is 2.43 and the sample variance of the floor 6 temperatures is 2.49 Calculate a suitable test statistic (using a pooled variance estimate) and test, at the 5% significance level, whether or not the average temperatures on the two floors are the same. (11 marks) (b) Members of a television consumer affairs programme audience select what they consider is the most important current consumer topic from a set of 6. Topic 1 Topic 2 Topic 3 Topic 4 Topic 5 Topic 6 20 30 26 14 1935 Calculate a suitable statistic and use it to test at the 5% level whether the results provide evidence of differences between the importance that members of the audience attach to the different topics (9 marks) (c) The weights of 25 new born babies in a hospital have a mean value of 3.44 kg, with a sample standard deviation of 0.970 kg. Find a 95% confidence interval for (5 marks) (Total 25 marks) the mean weight of babies in the population from which the 25 babies come.

Answer 1

Hell- tti 씨_u2_W5 fh:.ut丰从2. 1-93 ofThe audande to the different- topia 오 (Oi-Ei 20 ,24 、6667 12, 5833 24 1-5 2-3 3 26 24 0 1667 ti ena (al Xe_ 12. 6833 So raiect tto (07 19 2y 1.0417 635 50o ノuu 丿uu 12-5833 2.064 ( 느 3-4