Data and Displays · Medium problem

Reaction times (seconds) are shown in a stem-and-leaf plot with key $4 \mid 7 = 4.7$ seconds: $3 \mid 8~9$, $\ 4 \mid 1~4~4~7$, $\ 5 \mid 0~2~6$, $\ 6 \mid 3$. What is the range, in seconds?