Bags of a certain brand of tortilla chips claim to have a net weight of 14 oz.
Question:
Bags of a certain brand of tortilla chips claim to have a net weight of 14 oz. Net weights actually vary slightly from bag to bag. Assume net weights are Normally distributed. A representative of a consumer advocate group wishes to see if there is any evidence that the mean net weight is less than advertised and so intends to test the hypotheses H 0 : μ = 14, H a : μ < 14. To do this, he selects 16 bags of tortilla chips of this brand at random and determines the net weight of each. He finds a sample mean of 13.88 oz with a standard deviation of s = 0.24 oz.
1. Determine which of the following statements regarding the decision the representative would make is true:
A. He would not reject H 0 at a significance level of 0.05
B. He would reject H 0 at a significance level of 0.05 but not at 0.025
C. He would reject H 0 at a significance level of 0.025 but not at 0.01
2. 95% confidence interval for the population mean will be:
A. 13.88 +/- 0.1420
B. 13.88 +/- 0.1048
C. 13.88 +/- 0.5144
D. 13.88 +/- 0.1279
3. Suppose we were not sure if the distribution of net weights were normal. In which of the following circumstances would we not be safe using a t-procedure in this problem:
A. The mean and median of the data are nearly equal
B. A histogram of the data is moderately skewed
C. A box plot of the data shows the presence of a large outlier
Probability & Statistics for Engineers & Scientists
ISBN: 978-0130415295
7th Edition
Authors: Ronald E. Walpole, Raymond H. Myers, Sharon L. Myers, Keying