Question 1. You work for a consumer group that is looking at the longevity of laptop batteries. Your team runs an experiment that simulates normal usage of ten identical laptops from a well-known manufacturer and records the number of use/charge cycles until the battery life has deteriorated to less than 20% of its original value, by which point the laptop is deemed useless. (a) [4 marks] What are the types of censoring related to the current observation? (b) [6 marks] Calculate the Kaplan-Meier estimate for the "survival function" in terms of use/charge cycles given the following data: Laptop Use/charge cycles until 20% battery life 104 1 2 156 3 98 4 198 10 5 190* 6 290 7 156 8 104 9 200 10 37* Note that * indicates that the laptop's hard drive malfunctioned and the laptop became useless prior to battery failure. (c) [5 marks] Calculate a 99% confidence interval for the estimated probability that a laptop will survive for 250 use/charge cycles. Comment on your answer.