Question

The following table gives the distribution of the life time of 400 neon lamps:
Find the median life.
Light time(in hours) Number of lamps1500-2000 142000-2500 562500-3000 603000-3500 863500-4000 744000-4500 624500-5000 48

Answer 1

Median of life = 3406.97

Given:

Light time(in hours) 1500-2000    2000-2500   2500-3000   3000-3500

                                3500-4000    4000-4500   4500-5000

Number of lamps    14   56   60   86   74   62   48

To find:

Median of life.                      

From the given data:

See the table below attached

The median class is 3000-3500

Lower frequency (L) = 3000, Difference(h) = 500, N=400, f=86 and cf=130

$Median = L + (\frac{\frac{N}{2} - cf }{f} )\times h$

$Median = 3000+ (\frac{\frac{400}{2} - 130 }{86} )\times 500$

$Median = 3000+ (\frac{{200} - 130 }{86} )\times 500$

Median = 3000 + 406.96

Median = 3406.96

Therefore, the median is 3406.96.

To learn more....

1. The following is the distribution of height of students of certain class in a certain city: Find the average height of maximum number of students.

Height(in cms): 160-162 163-165 166-168 169-171 172-174

No.of students: 15 118 142 127 18

brainly.in/question/15924910

2. The following is the distribution of height of students of certain class in a certain city: Find the average height of maximum number of students.

Height(in cms): 160-162 163-165 166-168 169-171 172-174

No.of students: 15 118 142 127 18

brainly.in/question/15924910