Oil content of fried sweet potato chips. Refer to the Journal of Food Engineering (September 2013) study of the characteristics of sweet potato chips fried at different temperatures, Exercise 6.9719 (p. 347). Recall that a sample of 6 sweet potato slices were fried at 130° using a vacuum fryer, and the internal oil content (gigagrams [Gg]) was measured for each slice. The results were:
- a. Conduct a test of hypothesis to determine if the standard deviation, , of the population of internal oil contents for sweet potato slices fried at 130° differs from .1. Use α = .05.
- b. In Exercise 6.97, you formed a 95% confidence interval for the true standard deviation of the internal oil content distribution for the sweet potato chips. Use this interval to make an inference about whether σ = .1. Does the result agree with the test, part a?
6.97 Oil content of fried sweet potato chips. The characteristics of sweet potato chips fried at different temperatures were investigated in the Journal of Food Engineering (September 2013). A sample of 6 sweet potato slices were fried at 130° using a vacuum fryer. One characteristic of interest to the researchers was internal oil content (measured in millions of grams). The results were:
- a. Identify the target parameter, in symbols and words.
- b. Compute a 95% confidence interval for σ2.
- c. What does it mean to say that the target parameter lies within the interval with “95% confidence”?
- d. What assumption about the data must be satisfied in order for the confidence interval to be valid?
- e. To obtain a practical interpretation of the interval, part b, explain why a confidence interval for the standard deviation, σ, is desired.
- f. Use the results, part b, to compute a 95% confidence interval for σ. Give a practical interpretation of the interval.
Want to see the full answer?
Check out a sample textbook solutionChapter 7 Solutions
Statistics Sta 2122 Second Custom Edition For Florida International University
- The article “Effect of Internal Gas Pressure on the Com- pression Strength of Beverage Cans and Plastic Bottles” (J. of Testing and Evaluation, 1993: 129–131) includes the accompanying data on compression strength (lb) for a sample of 12-oz aluminum cans filled with strawberry drink and another sample filled with cola. Does the data suggest that the extra carbonation of cola results in a higher average compression strength? Base your answer on a P-value. What assumptions are necessary for your analysis? ( use ? = 0.01 )arrow_forwardA study was done to compare the flu incidence rates at the sart and at the end of winter of a given year. A sample of 100 persons were asked for incidence of flu twice: once at the start and once at the end of winter. Sample data were as follows: a. Give 99% CI for the difference in flu incidence rates at the start and at the end of winter? b. Compute a measure of association between flue incidence at the start and at the end of winter?arrow_forwardResearchers interested in lead exposure due to car exhaust sampled the blood of 52 police officers subjected to constant inhalation of automobile exhaust fumes while working traffic enforcement in a primarily urban environment. The blood samples of these officers had an average lead concentration of 124.32 µg/l and a SD of 37.74 µg/l; a previous study of individuals from a nearby suburb, with no history of exposure, found an average blood level concentration of 35 µg/l. Based on your preceding result, without performing a calculation, would a 99% confidence interval for the average blood concentration level of police officers contain 35 µg/l? Based on your preceding result, without performing a calculation, would a 99% confidence interval for this difference contain 0? Explain why or why not.arrow_forward
- A z-score of –1.6 has a corresponding Stanine score of:arrow_forwardWhat is the critical value? Wj\hat is the p value?arrow_forwardThe sulfate ion concentration in natural water can be determined by measuring the turbidity that results when an excess of BaCl2 is added to a measured quantity of the sample. A turbiditimeter, the instrument used for this analysis, was calibrated with a series of standard Na2SO4 solutions. The following data were obtained for the calibration:arrow_forward
- After doing AVONA on the SPSS I got result of sig. 0.165. What does that say about my data and hypothesis? How should I comment on it?arrow_forwardThe amount of oxygen consumption (ml/min) was measured in 6 individuals over two 10- minute periods while sitting with their eyes closed. During the first period, they listen to an exciting adventure story and then again, an hour later while they heard restful music. Based on the results shown, is oxygen consumption different depending on whether it is a story or music one is listening to? The data is in Table 2 and test at an alpha of 0.05. -Do using formulas not excelarrow_forwardMuch concern has been expressed regarding the practice of using nitrates as meat preservatives. In one study involving possible effects of these chemicals, bacteria cultures were grown in a medium containing nitrates. The rate of uptake of radio-labeled amino acid (in dpm, disintegrations per minute) was then determined for each culture, yielding the following observations. 7,255 6,875 9,637 6,863 9,098 5,846 8,954 7,979 7,068 7,498 7,882 8,179 7,528 8,728 7,469 Suppose that it is known that the mean rate of uptake for cultures without nitrates is 8,000. Do the data suggest that the addition of nitrates results in a decrease in the mean rate of uptake? Test the appropriate hypotheses using a significance level of 0.10. Find the test statistic and P-value. (Use technology to calculate the P-value. Round your test statistic to two decimal places and your P-value to three decimal places.) t= P-value= State your conclusion. Reject H0. We have convincing evidence that the mean rate of…arrow_forward
- In a sample of 300 steel rods, the correlation coefficient between diameter and length was r = 0.15. Find the P-value for testing H0: ρ ≤ 0 vs. H1: ρ > 0. Can you conclude that ρ > 0? Does the result in part (a) allow you to conclude that there is a strong correlation between eccentricity and smoothness? Explain.arrow_forwardUsing 1% & 5% alphas, test the overall significance of the model on excel.arrow_forwardResearchers interested in lead exposure due to car exhaust sampled the blood of 52 police officers subjected to constant inhalation of automobile exhaust fumes while working traffic enforcement in a primarily urban environment. The blood samples of these officers had an average lead concentration of 124.32 µg/l and a SD of 37.74 µg/l; a previous study of individuals from a nearby suburb, with no history of exposure, found an average blood level concentration of 35 µg/l. Test the hypothesis that the downtown police officers have a higher lead exposure than the group in the previous study. Interpret your results in context. Based on your preceding result, without performing a calculation, would a 99% confidence interval for the average blood concentration level of police officers contain 35 µg/l? Based on your preceding result, without performing a calculation, would a 99% confidence interval for this difference contain 0? Explain why or why not.arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill