Still assuming normality, estimate the probability p that a patient’s latency time will be at least 8 years?

Infectious Disease

A cohort of hemophiliacs is followed to elicit information on the distribution of time to onset of AIDS following seroconversion (referred to as latency time). All patients who seroconvert become symptomatic within 10 years, according to the distribution in Table 6.13.

Table 6.13: Latency time to AIDS among hemophiliacs who become HIV positive

Latency time (years) ______________ Number of patients

0 ………………………………………………… 2

1 ………………………………………………… 6

2 ………………………………………………… 9

3 …..…………………………………………… 33

4 ……………………………………………..… 49

5 ……………………………………………….. 66

6 …….…………………………………………. 52

7 ………………………………………………. 37

8 ………………………………………………. 18

9 ………………………………………………. 11

10 ……………………………………………… 4