- Provide A Formal Write Up For Each Requested Confidence Interval Include In Your Statement The Sample Average Or Propo 1 (215.33 KiB) Viewed 49 times
Provide a formal write-up for each requested confidence interval. Include in your statement: the sample average or proportion the interval is based on, the level of confidence, a description of what you are measuring in the interval, and the lower & upper limits. For example, “Based on a sample average of 75.6, there is a 95% probability that the mean test score on the first exam in Econ2210 is between 73.1 and 78.1. 1. A consumer's advocate group would like to evaluate the average energy efficiency rating (EER) of window-mounted, large-capacity air-conditioning units. A random sample of the EER for 36 units is contained in the data file EER.xls. Write a 90% confidence interval for mean EER 2. A plastic manufacturer wants to evaluate the durability of rectangular molded plastic blocks that are to be used in furniture. Data listing the hardness (in Brinell units) of 50 plastic blocks are provided in the data file PLASTIC.xls. Write a 99% confidence interval for mean hardness of the plastic blocks. I 3. A tea manufacturer claims that its tea bags contain an average of 5.0 grams of tea. The data file TEA2.xls lists the weight of the tea found in 105 tea bags. Write an 85% confidence interval for mean tea bag content. 4. An automobile dealer wants information regarding the proportion of customers who still own the car they purchased 5 years earlier. A random sample of 200 customers finds that 92 still own the car they purchased 5 years earlier. Write a 95% confidence interval for the population proportion.