In country A the vast majority 90 of companies in the chemic

In country A, the vast majority (90%) of companies in the chemical industry are ISO 14001 certified. The ISO 14001 is an international standard for environmental management systems. An environmental group wished to estimate the percentage of country B\'s chemical companies that are ISO 14001 certified. Of the 550 chemical companies sampled, 407 are certified. What proportion of the sample reported being certified? Create a 99% confidence interval for the proportion of country B\'s chemical companies with ISO 14001 certification. (Be sure to check conditions.) Compare to the country A proportion. a) The sample proportion is (Type an integer or a decimal.)

Solution

(a) sample proportion is 360/500 = 0.72

(b) here we get the following number of outcomes

This gives the following as the confidence interval

= (0.67, 0.77). Notice that true parameter was 0.72, and we are close to what we expected.

c) Clearly, we choose \'option C\' as the companies in B (atmost 77%, 99% Confident) are less certified than A(90%)

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