Normal curve -

Ans. is 'a' i.e., Distribution of data is symmetrical Standard normal curveo It is also known as bell curve or Gaussian distribution.o The shape of the curve is like a bell - bell shaped curve.o The data are distributed symmetrically on either side of a central value.o Normal distribution curve looks symmetrical in the dispersion with the largest frequencies in the middle score and tapering down of frequencies towards the highest as well as the lowest score - No tail.o Normal distribution curve is based on mean and standard deviation.o Mean median and mode all coincide - No skew,o Mean = median = mode = 0o Total area of curve is 1.o Its standard deviation is 1.o Variance is 1.