Suppose that among 24,839 customers of a certain company, exactly 11,842 feel very satised with the service they received. In order to estimate the satisfaction levels of the customers, a manager contacts a random sample of 80 of these customers and nds out how many of them were very satised. What is the probability that the managers estimate of the proportion of very satised customers in this group is within 0.10 of the true value?
Proportion The proportion in some category is found by Proportions are also called relative frequencies, and we can display them in a relative frequency table. The proportions in a relative frequency table will add to 1 (or approximately 1 if there is some roundoff error). Relative frequencies allow us to make comparisons without referring to the sample size. One Categorical Variable Of the n=2625 people who responded to the survey, 735 agree with the statement that there is only one true love for each person, while 1812 disagree and 78 say they don't know. Table 2.1 displays these results in a frequency table, which gives the counts in each category of a categorical variable. Table 2.1 A frequency table: Is there one true