The table shows some information about the lifetimes,
t, in hours, of some lightbulbs.

Lifetime Frequency
25 50 <
t≤ 100 69
100 <
t
≤ 150 31
150 <
t
≤ 200 4
200 <
t
≤ 250 0
250 <
t
≤ 300 4
300 <
t
≤ 350 11

Estimate the mean lifetime of a bulb.
Give your answer rounded to 2 DP.