The following table gives the distribution of the life time of 400 neon lamps: Light time (in hours) Number of lamps 1500-2000 14 2000-2500 56 2500-3000 60 3000-3500 86 3500-4000 74 4000-4500 62 4500-5000 48 Find the median life.

Question

Philoid · Accepted Answer

We can find cumulative frequencies with their respective class intervals as below:

Life time	Number of lams	Cumulative frequency
1500-2000	14	14
2000-2500	56	70
2500-3000	60	130
3000-3500	86	216
3500-4000	74	290
4000-4500	62	352
4500-5000	48	400
	N = 400

Median class = 3000-3500

l = 3000, f = 86, F = 130, h = 500

Median = l + * h

= 3000 +

= 3406.98 hours

So, median life time is 3406.98 hours.

Light time (in hours)	Number of lamps
1500-2000	14
2000-2500	56
2500-3000	60
3000-3500	86
3500-4000	74
4000-4500	62
4500-5000	48

The following table gives the distribution of the life time of 400 neon lamps:Light time (in hours)Number of lamps1500-2000142000-2500562500-3000603000-3500863500-4000744000-4500624500-500048Find the median life.

The following table gives the distribution of the life time of 400 neon lamps:

Light time (in hours)

Number of lamps

1500-2000

14

2000-2500

56

2500-3000

60

3000-3500

86

3500-4000

74

4000-4500

62

4500-5000

48

Find the median life.