[填空题]
The lifetime, in thousand of hours, of LED bulbs a(ryg b)pc;g/kt a manufasv bf 44scem5c3w 4dsdj*.5sxcture plant were recorded for a p4b 4cs3 sc.md fvwx *s55e4sjderiodic quality check. The data is illustrated 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.
