Graph to compare two quantitative data is?: (A) Histogram, (B) Scatter diagram, (C) Line Diagram, (D) Frequency curve
Answer is B. - scatter maps show the relationship between two variables - if dots cluster round a straight line, it shows evidence of relationship of a linear nature. If there is no such cluster, it is probable that there is no relationship between the variables. Reference : Park's textbook of preventive and social medicine, 23rd edition, pg no:847