Question

The following table gives the life times of neon lamps:
$\begin{array}{cc}\text{Length (in hours)}& \text{Number of lamps}\\ 300-400& 14\\ 400-500& 56\\ 500-600& 60\\ 600-700& 86\\ 700-800& 74\\ 800-900& 62\\ 900-1000& 48\end{array}$
(i) Represent the given information with the help of a histogram.
(ii) How many lamps have a life time of more than 700 hours?

Answer 1

(i) By taking life time (in hours) of neon lamps on x-axis and the number of
lamps on y-axis, the histogram of the given information can be drawn as follows.
(ii) It can be concluded that the number of neon lamps having their life time more than 700 is the sum of the number of neon lamps having their life time as 700−800, 800 − 900, and 900−1000.
Therefore, the number of neon lamps having their life time more than 700 hours is 184. (74 + 62+48 = 184)