How large a sample is needed
Contingency Table
A contingency table can be defined as the visual representation of the relationship between two or more categorical variables that can be evaluated and registered. It is a categorical version of the scatterplot, which is used to investigate the linear relationship between two variables. A contingency table is indeed a type of frequency distribution table that displays two variables at the same time.
Binomial Distribution
Binomial is an algebraic expression of the sum or the difference of two terms. Before knowing about binomial distribution, we must know about the binomial theorem.
A researcher wishes to estimate the proportion of households with two cars.
a) How large a sample is needed in order to be 99% confident that the sample proportion will not differ from the true proportion by more than 3%?
b) Repear part a if a previous study indicates that the proportion of households with two cars is 25%.
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