4. A bag containing 60 sweets is opened. The bag contains sweets of the following colours. Colour Red Frequency 18 Orange 17 Green 10 Purple Blue 9 6 According to the manufacturer, the various colours should have the following percentages. Colour Red Percentage 35% Orange 25% Green 20% Purple 15% Blue 5% Calculate the expected number of sweets of each colour in a bag containing exactly 60 sweets. Before you can perform the chi-squared test on this data, it is necessary to combine the data for one of the colours with that of another colour. (b) Which colour is this and why is this necessary? (c) Using the chi-squared test at the 5% significance level, investigate the hypothesis that the sweets in the packet may be regarded as a random sample. Remember to state the null hypothesis, the number of degrees of freedom and the critical value of chi-squared.