ABSTRACT
Tensile force (kN) 4.8 9.3 12.8 17.7 21.6 26.0 Extension (mm) 3.5 8.2 10.1 15.6 18.4 20.8
Assuming a linear relationship:
(a) determine the equation of the regression line of extension on force,
(b) determine the equation of the regression line of force on extension,
(c) estimate (i) the value of extension when the force is 16 kN, and (ii) the value of force when the extension is 17 mm. (23)
3. 1200 metal bolts have a mean mass of 7.2 g and a standard deviation of 0.3 g. Determine the standard error of the means. Calculate also the probability that a sample of 60 bolts chosen at random, without replacement, will have a mass of (a) between 7.1 g and 7.25 g, and (b) more than 7.3 g. (11)
4. A sample of 10 measurements of the length of a component are made and the mean of the sample is 3.650 cm. The standard deviation of the samples is 0.030 cm. Determine (a) the 99% confidence limits, and (b) the 90% confidence limits for an estimate of the actual length of the component. (10)
For lecturers/instructors/teachers, fully worked solutions to each of the problems in Revision Test 12, together with a full marking scheme, are available at the website:
