During a year-long cybersecurity breach, about 1,000 remote employees at Firm Z reported their accounts had been compromised. Around the same number of on-site employees also reported compromised accounts. Based on these figures, it can be hypothesized that working remotely was no more vulnerable to security breaches than working on-site.
Which of the following, if it could be carried out, would be most useful in an evaluation of the above hypothesis?