[填空题]
The lifetime, in thousand of hours, of LED bulbs at a manufactq93/4c r yd 8ysfmq/8cgu2gr tus - 09kefgy/54gqfktqqd8a3cre plant were recorded for a periodic quality check. The data is illustrated93 q0tf fsakd58gy 4qe-cgk/q in the box-and-whisker diagram shown below.
1. Write down the median lifetime of these LED bulbs. hours
2. Write down the upper quartile. hours
3. Find the interquartile range.
The lifetimes of these LED bulbs are normally distributed.
4. Find the longest lifetime of an LED bulb that is still not considered an outlier.
