Assertion (A): A histogram has no gaps between its bars. Reason (R): Histograms are drawn for continuous (grouped) data where class boundaries meet. Which is correct?

Class 9StatisticsStatistics and Probability

ABoth A and R are true and R correctly explains A
BBoth A and R are true but R does not explain A
CA is true but R is false
DA is false but R is true

Step-by-Step Solution

Histogram bars touch with no gaps because the class intervals are continuous, so R correctly explains A.

Answer: A) Both A and R are true and R correctly explains A

Key idea: Histogram vs bar graph

Both look like bars, but they differ:

**Bar graph**: For DISCRETE / categorical data (favourite colour, sport, etc.). Bars have GAPS between them. Width has no meaning.

**Histogram**: For CONTINUOUS / grouped data with class intervals. Bars TOUCH (no gaps), reflecting that the class boundaries are continuous. Bar WIDTH represents class size; HEIGHT represents frequency.

**Frequency polygon**: connect the midpoints (class marks) of the tops of histogram bars to form a line graph. Useful for comparing two distributions on the same axes.

**Key rule**: histogram bars must have no gaps; bar graph bars MUST have gaps.

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