Alice and Bob are independently annotating movie reviews into POS (for positive) and NEG (for negative) sentiment. They compared their results and have the following finding: Number of reviews that both Alice and Bob labeled POS: 40 Number of reviews that Alice labeled POS but Bob labeled NEG: 10 Number of reviews that Alice labeled NEG but Bob labeled POS: 20 Number of reviews both Alice and Bob labeled NEG: 30 They then computed the Cohen's Kappa value to measure their Inter-annotator agreement. What is their Kappa agreement rate