A cybersecurity analyst is tasked with assessing the security posture of a company\'s network. They decide to utilize a vulnerability scanning tool to identify potential weaknesses. After running the scan, the tool reports several vulnerabilities categorized by severity levels: critical, high, medium, and low. The analyst needs to prioritize remediation efforts based on the potential impact of these vulnerabilities. If the critical vulnerabilities are estimated to have a 90% likelihood of exploitation and a potential impact score of 9 out of 10, while high vulnerabilities have a 70% likelihood and an impact score of 7, how should the analyst calculate the risk score for each category to determine which vulnerabilities to address first?