The table shows some information about the lifetimes, t , in hours, of some lightbulbs. Lifetime Frequency 25 < t ≤ 50 47 50 < t ≤ 100 86 100 < t ≤ 150 45 150 < t ≤ 200 36 200 < t ≤ 250 0 250 < t ≤ 300 37 300 < t ≤ 350 50 Estimate the mean lifetime of a bulb. Give your answer rounded to 2 DP.