Final answer:
The mean survival time for the 4 patients with hepatic angiosarcoma is 7 months.
Step-by-step explanation:
To find the mean survival time for the 4 patients with hepatic angiosarcoma, we need to calculate the average of the given survival times.
The mean is calculated by adding up all the survival times and dividing the sum by the number of patients.
In this case, the sum of the survival times is 5 + 19 + 1 + 3 = 28 months. Since there are 4 patients, the mean survival time is 28/4 = 7 months.