Listed below are the amounts of mercury in parts per million

Listed below are the amounts of mercury (in parts per million, or ppm) found in tuna sushi Sampled at different stores. The sample mean is 1.184 ppm and the sample standard deviation is 0.249 ppm. Use technology to construct a 90% confidence interval estimate of the mean amount of mercury in the population. 0.95 0.86 1.13 1.49 1.43 1.38 1.05

Solution

Steps in Excel:

Enter data in a column

Go to data analysis data

then select \"Descriptive statistics\"

Select data, check and enter confidence level 90%, and also check summary statistics check box.

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Using Excel following output is created for confidence interval and summary statistics:

Last entry in th ebaove output shows the margin of errro of 90% confidence interval:

ME=0.183

So required 90% confidence inetrval is :

Lower limit: 1.001

Upper limit: 1.367