The standard normal distribution:

Normal Distribution: Is also known as &;Gaussian distribution&; or &;Standard distribution&; Type of distribution: Is the distribution of values of a quantitative variable such that they are symmetric with respect to a middle value with same mean, median and mode, and then the frequencies taper off rapidly and symmetrically on both sides- &;bell shaped distribution&; Fig: Normal curve showing distribution of values Normal or Gaussian curve Is &;bilaterally symmetrical and bell-shaped Is based on Mean and standard detion Mean, Median and Mode coincide (Mean=Median=Mode) Has mean (m ) = 0 and SD(s) = 1 Mean +- 1SD (m +-1s) covers 68% values Mean +- 2SD (m +-2s) covers 95% values Mean +- 3SD (m +-3s) Covers 99% values In a normal distribution, 50% values lie above mean & 50 % below mean. Ref: Park 25th edition Pgno: 912