Please assist with question 5

An investor on the JSE held a 2: 3: 1: 4 ratio of equities between the mining, industrial, retail and financial sectors in 2015. In 2020, of the 4 500 shares that she currently holds, 900 shares are in mining companies, 1 400 shares are in industrial companies, 400 shares are in retail companies, and the rest in financial companies. Has this investor changed her portfolio mix substantially since 2015? Use the chi-squared goodness-of-fit test to test the hypothesis, at the 5% significance level, that there has been no significant change in portfolio mix since 2015. What is the critical value? Select one: O a. 2.65 O b. 1.96 O c. 3 O d. 7.815