QUESTION 4 In general, an experienced quality control inspector of measurement of sheet metal stamping would have a variance of 0.18 (inch)². A new joint inspector measures 101 stampings with variance...

Extracted text: QUESTION 4 In general, an experienced quality control inspector of measurement of sheet metal stamping would have a variance of 0.18 (inch)². A new joint inspector measures 101 stampings with variance of 0.165 (inch)². Assume data is normally distributed, by using 95% significance level, test whether the new joint inspector is making satisfactory measurements. QUESTION 5 A marketing study was done on consumer from two age groups for their spending on 20 categories of consumer items. Based on 15 respondents in the 18 – 34 age group, the average spending is RM76.40 with a variance of RM25.30. Meanwhile, based on 18 respondents in the 35+ group, the mean and variance were RM71.20 and RM22.20 respectively. By assuming the population variance are not equal, test if there is any difference in the mean spending between these two populations in 95% significance level.