In: Statistics and Probability
The Pizza Shop wanted to determine what proportion of its customers ordered only cheese pizza. Out of 80 random customers surveyed, 20 ordered cheese pizza. Find the conditions that satisfy to make a confidence interval estimate for the true proportion of customers who order only chees pizza.
Correct answer: np = 20 > 5, nq = 60 > 5
How does one get to the correct answer and why is it correct?
Solution:
-> np > 5 & nq > 5 is a condition made in order to estimate/analyse what should be true for the normal distribution approximation to be good enough.
If this condition is met, it also signifies that the sample size taken is sufficiently large so that the data is normally distributed...
Generally a sample size is more than or equal to 30, it is considered to be a large sample and the data is assumed to be normally distributed... For np and nq to increase 'n' must definitely increase, where 'n' is the number of trials. So, it should be clear that the more trials (independent) are made, the more accurate your approximation will be...
Solution to the above Numerical:
End of the Solution...