A student asked me to explain this question from a previous year (high school) exam paper today. Fundamentally the question itself if very straight forward, however I thought it was quite poorly worded and perhaps open to misinterpretation. I'm wondering if anyone else thinks it a little ambiguous or if it's just me. Heres the question. --------------- The manufacturer’s specifications state that the life of their light globes is normally distributed with a standard deviation of 170 hours. What is the mean life, in hours, of these light globes if 97.5% will last up to 5000 hours? --------------- The thing that I don't like about this question is that longevity specifications are usually in the form of "9x percent will last at least y hours, whereas here they seem to be saying that they will last at most this many hours. Does anyone else think that statement "if 97.5% will last up to 5000 hours" could have been better worded. I interpreted it as meaning that 97.5% will last at most 5000 hours but I'm wondering if anyone else here might have interpreted it the other way around?