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3 steps for p-value ( p value ) analysis


 p-value:
=======
Probability (or the area) at the tail of a bell shaped curve, where,

    center of bell = population mean,
    marker = sample mean
    p-value = area remaining at the tail after deducting the are
 
intuition:
=========
the lower the area ==> the higher the distance between centre and sample mean . So, we can reject hypothesis.

Steps to calculate p-value


1. Assume null hypethesis ( i.e.  Population mean)
====================================
It( actually the opposite of this ) will be the Null Hypothesis

2. Calculate sample statistics
=====================
Now, calculate statistics from available data.

3. Calculate p-value
==================
If p-value is small ==> distance between population mean and sample mean is high ==> Reject Null Hypo

If p-value is big==> distance between population mean and sample mean is small ==>Fail to Reject Null Hypo



         Fig : p-value (source: wiki )


As, we can not accept a null hypothesis() , we try to reject null hypo. So, it is wise to use the hypo opposite to what we are trying to establish as Null Hypo.

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