Q.Normal distribution was invented by :

Normal Distribution

The normal (or Gaussian) distribution is a continuous probability distribution whose density curve is the familiar symmetric, bell-shaped curve. A random variable $X$ that is normally distributed with mean $\mu$ and standard deviation $\sigma$ is written $X \sim N(\mu, \sigma^2)$, and its density is

The curve is symmetric about $\mu$, and the total area beneath it is $1$. Roughly $68\%$, $95\%$ and $99.7\%$ of the data lie within one, two and three standard deviations of the mean respectively. …