Suppose you are working for a pharmaceutical company and are concerned about the amount of fluctuation in bottles of a particular cough syrup the company produces. You randomly select and measure the contents of 15 bottles of the syrup and find a sample mean amount of 4.2483 ounces with sample standard deviation of 0.0321 ounces. You also know the distribution of cough syrup amounts is normal.
a) Construct a interval estimate for the population standard deviation for the amounts of cough syrup. Use a 90% confidence level. Round the interval limits to the nearest ten-thousandth. Make sure you interpret your interval estimate with a sentence and that you state the critical values that are used to find the interval estimate.