Question

The following table gives the life time of 400 neon Lamps:
i) Represent the given information with the help of a histogram
ii) How many lamps have a lifetime 4 more than 700 hours?

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

Answer 1

Hint: Whenever we represent a set of data in a histogram, we need to check if the given data is continuous or discontinuous. If it is continuous, as of this problem, we can directly start plotting the graph. If the data is discontinuous, then we should convert it into continuous intervals and then plot a histogram

Complete step-by-step answer:
The Difference Between Bar Charts and Histograms
With bar charts, each column represents a group defined by a categorical variable; and with histograms, each column represents a group defined by a continuous, quantitative variable.
Histograms are used to show distributions of variables while bar charts are used to compare variables. Histograms plot quantitative data with ranges of the data grouped into bins or intervals while bar charts plot categorical data

(i) We shall take the life time along the X-axis and number of lamps along the Y-axis, keeping in mind the intervals.

(ii) Number of lamps having their life time more than 700 = number of lamps having life time in between 700 to 1000 = 700 to 800 + 800 to 900 + 900 to 1000
= 74+62 +48 = 184

Note: Remember that in order to draw a histogram, there should be continuous class intervals. Otherwise drawing a histogram is not possible. So, 4 the given data has discontinuous intervals, then convert it into continuous intervals and then plot the graph.