2nd group 750 die 11 : 1000 X X 1000 alive 250 alive 70 die 15 die lst group X X X n = 100 100 alive 30 alive 15 alive time Dec 1 Jan 1 Feb 1 Survival after irradiation does not depend on the season, but only on the time since radiation. Knowing this, and assuming that there are no differences in the two groups of mice other than the length of observation: 1 How would you estimate P[a mouse survives at least one month after irradiation]? 2. How would you estimate P[a mouse survives at least two months after irradiation] by using the data from the 15' group? 3. Could you improve the estimator in question 2 by including the data from the 2\"d group? Why not? Why yes? 4. How would you estimate P[a mouse survives at least 2 months after irradiation, given that it survived at least one month after irradiation]? 5. Is there any way you can use your answer to question 4 to help answer questions 2 and 3? (Hint: Use the definition of conditional probability: P[A given B] = P[A and B]/P[B].)