Sensitivity is the proportion of patients with disease who test positive. In probability notation: P(T+|D+) = TP / (TP+FN). Specificity is the proportion of patients without disease who test negative. In probability notation: P(T-|D-) = TN / (TN + FP). Pretest Probability is the estimated likelihood of disease before the test is done. It is the same thing as prior probability and is often estimated.
Billed as An Aquarian Exposition: 3 Days of Peace & Music, it was held at Max Yasgur's 600-acre (240 ha; 0.94 sq mi) dairy farm in the Catskills near the hamlet of White Lake in the town of Bethel. Bethel, in Sullivan County, is 43 miles (69 km) southwest of the town of Woodstock, New York, in adjoining Ulster County.
With about 220,000 people in attendance and another 10,000 working the festival, Woodstock '99 temporarily made the festival site the third most populated city in New York state. Now imagine turning off that city's water supply. With temperatures hovering from the high 80s to, in some accounts, hitting the 100s, water became a necessity.