🧮 Mathematics

Explanation: Standard deviation measures how spread out the values in a data set are from the mean. A low SD means data is clustered near the mean; a high SD means it is spread out.

Explanation: A fair coin has 2 outcomes (head or tail), each equally likely. P(head) = 1/2 = 0.5 = 50%. Probability ranges from 0 (impossible) to 1 (certain).

Explanation: The mode is the value that appears most frequently in a data set. A data set can have one mode (unimodal), more than one mode (multimodal), or no mode.

Explanation: Median is the middle value when data is sorted. For 3, 5, 7, 9, 11 (5 values), the median is the 3rd value = 7.

Explanation: Mean = Sum ÷ Count = (2+4+6+8+10) ÷ 5 = 30 ÷ 5 = 6. The mean (arithmetic average) is the most common measure of central tendency.

Explanation: The sum of interior angles of any quadrilateral is 360°. Formula: (n-2) × 180° where n = number of sides. (4-2) × 180° = 360°.

Explanation: A hexagon has 6 sides. Common shapes: triangle (3), quadrilateral (4), pentagon (5), hexagon (6), heptagon (7), octagon (8).

Explanation: The volume of a cube with side a is V = a³. The surface area of the same cube is 6a².

Explanation: The Pythagorean Theorem states: c² = a² + b², so c = ?(a² + b²). This applies only to right-angled triangles.

Explanation: The area of a circle is A = ?r², where r is the radius. The circumference (perimeter) is 2?r. These are fundamental circle formulae.