The table shows some information about the lifetimes,
t
, in hours, of some lightbulbs.
Lifetime Frequency
25 <
t
≤ 50 70
50 <
t
≤ 100 76
100 <
t
≤ 150 29
150 <
t
≤ 200 91
200 <
t
≤ 250 0
250 <
t
≤ 300 15
300 <
t
≤ 350 23
Estimate the mean lifetime of a bulb.
Give your answer rounded to 2 DP.