Question

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

Answer 1

Answer:

what is the frequency of 4500 - 5000

please tell me

then I solve your problem

Answer 2

Answer:

Dear Student:

Life time (in hours)       Number of lamps    Cumulative Frequency(cf)

 1500-2000                           14                            14

2000-2500                           56                   14+56 = 70

2500-3000                           60                    70+60=130

3000-3500                           86                   130+86=216

3500-4000                           74                    216+74=290

4000-4500                           62                   290+62=352

4500-5000                            48                   352+48=400

                                    ∑fi = 400

Median= l+({n}{2}-cf /f)h

Where, l =lower limit of median class=3000

            h=class interval=5000-4500=500

            n =∑fi

           f=frequency of the median class=86

          cf = cumulative frequency before median class=130

Median= 3000+\{400}{2}-130 }{86}*500

Median=3000+({200−130}/86)∗500

3000+70/86×500

3000+406.98

      Median  =3406.98

hope it helps you