[填空题]
The lifetime, in thousand of ho5rsyh3b;: t/lc ni s1lurstbiljx .jggq8h+ 31.-b soqt 3, of LED bulbs at a manufacture plant were recorded for a periodic quality check. The data is illustrated in the box-and-wsjx 1. g tg+q3itlboh-bqj38.hisker 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.
