एक पूर्ण सामान्य बंटन (Normal Distribution) में माध्य से एक मानक विचलन (±1σ) के भीतर लगभग कितने प्रतिशत आँकड़े आते हैं?

The area between z = -3 and z = +3 under the standard normal curve is approximately:

A normal probability curve is symmetrical about its mean. Therefore, its skewness is:

Arrange the following intervals of a standard normal variate (Z) in increasing order of their probabilities: A. 0 ≤ Z ≤ +1 B. +1 ≤ Z < +2 C. +2 ≤ Z < +3 D. +3 ≤ Z < +∞ Choose the correct answer from the options given below: