QUESTION 11 A full charged battery of a given mobile phone lasts a time T under...
QUESTION 11 A full charged battery of a given mobile phone lasts a time T under full utilization It was found that this lifetime T is normally distributed with a mean of 180 min and standard deviation of 20min. What value of lifetime in minutes is exceeded with 90% probability? 120.5 mn 134.4 mn 143.6 mn 154.3 mm 161.3 mn QUESTION 12 A full charged battery of a given mobile phone lasts a time T under full utilization It was found that this lifetime T is normally distributed with a mean of 180 min and standard deviation of 20min. A sample of 25 phones has been observed, what is the probability that the average lifetime is less than 188 min? 0.66