As a ruleofthumb, the samplingdistribution of the sampleproportion can be approximated by a normalprobability distribution whenever the samplesize is large.
<h3>What is the Central limit theorem?</h3>
The Centrallimittheorem says that the normalprobabilitydistribution is used to approximate the samplingdistribution of the sampleproportions and samplemeans whenever the sample size is large.
Approximation of the distribution occurs when the samplesize is greater than or equal to 30 and n(1 - p) ≥ 5.
Thus, as a ruleofthumb, the samplingdistribution of the sample proportions can be approximated by a normalprobabilitydistribution when the samplesize is large and each element is selected independently from the same population.
The total repair cost for each store is the cost of repairs added to the sales tax. The amount of money saved will be the difference between the two total costs.
