If the mean and the median pertaining to a certain character of a population are of the same value, the following is most likely to occur:-
- A normal distribution
- A T-shaped curve
- A skewed curve
- A bi-modal distribution
Answer
(1) A normal distribution
Solution
For a character showing continuous variation in a population, the frequency distribution is plotted against the value of the character.
⇒ In a normal (bell-shaped) distribution the curve is symmetrical about its peak, so mean = median = mode.
∵ In a skewed curve the mean is pulled towards the longer tail and differs from the median, and a bimodal distribution has two peaks.
∴ Equal mean and median indicate a normal distribution (as in the bell-shaped curves of NCERT showing stabilising selection).
Answer: (1)