that the population of weights of all the plastic medals is

Last updated: 6/5/2023

that the population of weights of all the plastic medals is approximately normally distributed The manufacturer claims that the standard deviation of this population is 0 23 grams You are a quality control specialist who wants to test this claim with a random sample of 21 plastic medals Based on your sample follow the steps below to construct a 90 confidence interval for the population standard deviation of the weights of all the plastic medals Then state whether the confidence interval you construct contradicts the manufacturer s claim If necessary consult a list of formulas a Click on Take Sample to see the results from the random sample Take Sample Point estimate of the population variance 1 Sample size 0 Left critical value 0 To find the confidence interval for the population standard deviation first find the confidence interval for the population variance Right critical value 0 Enter the values of the point estimate of the population variance the sample size the left critical value and the right critical value you need for your 90 confidence interval for the population variance Choose the correct critical values from the table of critical values provided When you are done select Compute Compute Number of plastic medals 21 Sample mean 0 00 34 87 0 00 90 confidence interval for the population variance Sample standard Sample variance deviation 0 46 90 confidence interval for the population standard deviation b Based on your sample graph the 90 confidence interval for the population standard deviation of the weights of all the plastic medals Critical values Left Right 0 995 7 434 0 005 39 997 X0 975 9 591 0 025 34 17 0 950 10 851 0 050 31 41 Enter the values for the lower and upper limits on the graph to show your confidence interval Round the values to two decimal places For the point enter the claim 0 23 made by the manufacturer on your graph 0 50 90 confidence interval for the population standard deviation 0 2116 O No the confidence interval does not contradict the claim The claimed standard deviation 0 23 is inside the 90 confidence interval O No the confidence interval does not contradict the claim The claimed standard deviation 0 23 is outside the 90 confidence interval c Does the 90 confidence interval you constructed contradict the manufacturer s claim Choose the best answer from the choices below O Yes the confidence interval contradicts the claim The claimed standard deviation 0 23 is inside the 90 confidence interval X O Yes the confidence interval contradicts the claim The claimed standard deviation 0 23 is outside the 90 confidence interval X 5 1 00 1 00