Information that is known about the distribution (for example, known standard deviation) The pdf is symmetrical about its mean of zero.

However, it is more spread out and flatter at the apex than the normal distribution It approaches the standard normal distribution as n gets larger

Hypothesis — a statement about the value of a population parameter, in case of two hypotheses, the statement assumed to be true is called the null hypothesis (notation H 0 ) and the…. Hypothesis Testing — Based on sample evidence, a procedure for determining whether the hypothesis stated is a reasonable statement and should not be rejected, or is unreasonable and should be rejected. Normal Distribution — a continuous random variable (RV) with pdf f ( x ) = 1 σ 2 π e - ( x - μ ) 2 σ 2 f ( x ) = 1 σ 2 π e - ( x - μ ) 2 σ 2 , where μ is the mean of the distribution, and σ is the…. Standard Deviation — a number that is equal to the square root of the variance and measures how far data values are from their mean; notation: s for sample standard deviation and σ for population….