Question2. The paralympic committee of a sitting volleyball club has indicated that the mean score achieved by the sports' members in the past was 85.9. A group of members believes that recent changes to the sitting volleyball court have led to a change in the mean score achieved by the club's members and decides to investigate this belief. A random sample of the scores, $x$, of 100 club members was taken and is summarized by $$\sum x=8350 \quad \text { and } \quad \sum(x-\bar{x})^{2}=15321$$ where $\bar{x}$ denotes the sample mean. Test, at the $5 \%$ level of significance, the group's belief that the mean score of 85.9 has changed.