Page 87 - Mathematics Class - IX

OBSERVATIONS
Case A
1. The intervals are:

a – b = _______________, b – c = _______________, c – d = _______________
d – e = _______________, e – f = _______________, f – g = _______________, g – h = ___________

2. f = _______________, f = _______________, f = _______________, f = _____________,
1 2 3 4
f = _______________, f = _______________, f = _______________
5 6 7
Case B
1. The intervals are:

a – b = _______________, b – c = _______________, c – d = _______________
d – e = _______________, e – f = _______________, f – h = _______________
2. Modified Frequencies are:

F = _______________, F = _______________, F = _______________,
1 2 3
F = _______________, F = _______________, F = _______________,
4 5 6
INFERENCE

The two histograms show equal width and varying width, respectively.

EXTENDED TASK
1. Take larger data and show it using histogram.
2. Prepare a chart to bring out analytical difference in histogram, pie-chart and bar graph.

APPLICATION
Histograms are used to present large data pictorially in a concise way.

Viva-Voce

1. Define data.
Ans. Any facts or figures collected for any information is called data.
2. Name the types of data.

Ans. Raw data, grouped data and ungrouped data.
3. Which are the three measures of central tendencies?
Ans. Mean, median and mode.
4. Name any three ways to represent data.
Ans. Bar graph, histogram, pie charts.

5. Is it possible to draw frequency polygons without drawing histograms?
Ans. Yes.
6. Define histogram.

Ans. A histogram is a graphical representation of grouped distribution with continuous classes.

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