Fusible interlinings are being used with increasing frequency to support outer fabrics and improve the shape and drape of various pieces of clothing. The article “Compatibility of Outer and Fusible Interlining Fabrics in Tailored Garments” (Textile Res. J., 1997: 137–142) gave the accompanying data on extensibility (%) at 100 gm/cm for both high-quality (H) fabric and poor-quality (P) fabric specimens.
a. Construct normal
b. Construct a comparative box plot. Does it suggest that there is a difference between true average extensibility for high-quality fabric specimens and that for poor-quality specimens?
c. The sample mean and standard deviation for the high quality sample are 1.508 and .444, respectively, and those for the poor-quality sample are 1.588 and .530. Use the two-sample t test to decide whether true average extensibility differs for the two types of fabric
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Chapter 9 Solutions
Student Solutions Manual for Devore's Probability and Statistics for Engineering and the Sciences, 9th
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- Does buttered toast fall face down? Data was collected to test this. 40 slices of toast (each with butter on one side) were dropped (from the same height). 24 slices (60%) landed buttered side down. We would like to use the results of this study to determine if there is statistical evidence that toast tends to land buttered side down more than 50% of the time.arrow_forwardA 5-year study among 601 participants with retinitis pigmentosa assessed the effects of high-dose vitamin A (15,000 IU per day) and vitamin E (400 IU per day) on the course of their disease. One issue is to what extent supplementation with vitamin A affected their serum-retinol levels. The test used to analyze the effects of vitamins assumes that the distribution of serum retinol is approximately normal. To verify this assumption, the investigators obtained a frequency distribution of serum retinol at year O among males in the vitamin A group, with data as shown in the table below. The mean serum retinol for the group was 1.89 and the standard deviation was 0.36. n Serum- retinol group (μmol/L) ≤1.405 6 1.405-1.755 22 1.755-2.105 22 2.105-2.455 20 ≥2.455 3 1. Perform a statistical test to check on the normality assumption. Given your results, do you feel the assumption of normality is warranted? Why or why not?arrow_forwardThe degenerative disease osteoarthritis most frequently affects weight-bearing joints such as knee. The article “Evidence of Mechanical Load Redistribution at the Knee Joint in the Elderly when Ascending Stairs and Ramps” (Annals of Biomed. Engr., 2008:467-476) presented the following summary data on stance duration (ms) for samples of both older and younger adults. Age Sample Size Sample Mean Sample SD Older 28 801 117 Younger 16 780 72 Assume that both stance duration distributions are normal. Carry out a test of hypotheses at significance level .05 to decide whether true average stance duration is larger among elderly individuals than among younger individuals. (Population variances are not assumed equal.)arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill