For drawing a frequency polygon of a continuous frequency distribution, we plot the points whose ordinates are the frequencies of the respective classes and abscissae are respectively :

1. upper limits of the classes

2. lower limits of the classes

3. class marks of the classes

4. upper limits of preceding classes

Median of the numbers 4, 4, 5, 7, 6, 7, 7, 3, 12 is

1. 4

2. 5

3. 6

4. 7

In a data, 10 numbers are arranged in ascending order. If the 8th entry is increased by 6, then the median increases by

1. 0

2. 2

3. 3

4. 6

Consider the following two statements.

Statement 1: A histogram consists of a set of adjacent rectangles whose bases are equal to class size, and heights are equal to class frequencies.

Statement 2: In a bar graph, the breadth of a rectangle has no significance, whereas in a histogram, the breadth of a rectangle is meaningful and it represents the class size.

Which of the following is valid?

1. Both the statements are true.

2. Both the statements are false.

3. Statement 1 is true, and Statement 2 is false.

4. Statement 1 is false, and Statement 2 is true.