The following table gives the life times of 400 neon lamps .Find the mean lifetime
Life time (in hours) Number of lamps
301 - 400 14
401 - 500 56
501 - 600 60
601 - 700 86
701 - 800 74
801 - 900 62
901 - 1000 48

Open in App

Solution

$x_{i} = 350, 450, 550, 650, 750, 850, 950 \sum f_{i} = 400 \sum x_{i} f_{i} = 4900 + 25200 + 33000 + 55900 + 63000 + 55500 + 45600 = 283100 ¯ x = \frac{283100}{400} = 707.75$

Suggest Corrections

Similar questions

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

$\begin{matrix} L i f e t i m e (i n h o u r s) & N u m b e r o f l a m p s 1500 - 2000 & 14 2000 - 2500 & 56 2500 - 3000 & 60 3000 - 3500 & 86 3500 - 4000 & 74 4000 - 4500 & 62 4500 - 5000 & 48 \end{matrix}$

Find the median life time of a lamp.

Question 5
The following table gives the distribution of the life time of 400 neon lamps:

Find the median life time of a lamp.

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

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

Find the median life time of a lamp.

The following table gives the life times of 400 neon lamps :

(i)

Represent the given information with the help of histogram.

Life time (in hours)	Number of lamps
$300 - 400$	$14$
$400 - 500$	$56$
$500 - 600$	$60$
$600 - 700$	$86$
$700 - 800$	$74$
$800 - 900$	$62$
$900 - 1000$	$48$

(i i)

How many lamps have a life time more than

700

hours?

Question 5 (ii)
The following table gives the life times of neon lamps:
$\begin{matrix} Length (in hours) & Number of lamps 300 - 400 & 14 400 - 500 & 56 500 - 600 & 60 600 - 700 & 86 700 - 800 & 74 800 - 900 & 62 900 - 1000 & 48 \end{matrix}$
(ii) How many lamps have a life time of more than 700 hours?

Join BYJU'S Learning Program

Life time (in hours)	Number of lamps
301 - 400	14
401 - 500	56
501 - 600	60
601 - 700	86
701 - 800	74
801 - 900	62
901 - 1000	48

The following table gives the life times of 400 neon lamps .Find the mean lifetime Life time (in hours)Number of lamps301 - 40014401 - 50056501 - 60060601 - 70086701 - 80074801 - 90062901 - 100048

xi=350,450,550,650,750,850,950∑fi=400∑xifi=4900+25200+33000+55900+63000+55500+45600=283100¯x=283100400=707.75

The following table gives the life times of 400 neon lamps .Find the mean lifetime
Life time (in hours) Number of lamps
301 - 400 14
401 - 500 56
501 - 600 60
601 - 700 86
701 - 800 74
801 - 900 62
901 - 1000 48

$x_{i} = 350, 450, 550, 650, 750, 850, 950 \sum f_{i} = 400 \sum x_{i} f_{i} = 4900 + 25200 + 33000 + 55900 + 63000 + 55500 + 45600 = 283100 ¯ x = \frac{283100}{400} = 707.75$