Fasteners used in aircraft manufacturing are slightly crimped so that they lock enough to avoid loosening during vibration. Suppose that 55% of all fasteners pass an initial inspection. Of the 45% that fail, 10% are so seriously defective that they must be scrapped. The remaining fasteners are sent to a recrimping operation, where 40% cannot be salvaged and are discarded. The other 60% of these fasteners are corrected by the recrimping process and subsequently pass inspection. (a) What is the probability that a randomly selected incoming fastener will pass inspection either initially or after recrimping? (b) Given that a fastener passed inspection, what is the probability that it passed the initial inspection and did not need recrimping? (Round your answer to four decimal places.)

In the process of producing engine valves, the valves are subjected to a first grind. Valves whose thicknesses are within the specification are ready for installation. Those valves whose thicknesses are above the specification are reground, while those whose thicknesses are below the specification are scrapped. Assume that after the first grind, 74% of the valves meet the specification, 18% are reground, and 8% are scrapped. Furthermore, assume that of those valves that are reground, 88% meet the specification, and 12% are scrapped.   Draw a tree diagram to represent the situation Find the probability that a valve is ground only once Given that a valve is not reground, what is the probability that it is scrapped? Find the probability that a valve is scrapped Given that a valve is scrapped, what is the probability that it was ground twice? Find the probability that the valve meets the specification (after either the first or second grind). Given that a valve meets the specification…

A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1482 and the standard deviation was 315. The test scores of four students selected at random are 1910, 1200, 2210, and 1390. Find the z-scores that correspond to each value and determine whether any of the values are unusual. The z-score for 1910 is (Round to two decimal places as needed.)

Annabel, a retail analyst, has been following Under Armour, Incorporated, the pioneer in the compression-gear market. Compression garments are meant to keep moisture away from a wearer's body during athletic activities in warm and cool weather. Annabel believes that the Under Armour brand attracts a younger customer relative to other companies. The accompanying file includes data on the age of the customers and whether or not they purchased Under Armour (Purchase; 1 for purchase. 0 otherwise). Click here for the Excel Data File *-1. Use the appropriate statistical software to estimate a logistic regression model using Under Armour as the response variable and age as the predictor variable. Note: Negative values should be indicated by a minus sign. Round your answers to 2 decimal places. Intercept Age Coefficient a-2. Compute the predicted probability of an Under Armour purchase for a 20-year-old customer and a 30-year-old customer. Note: Round coefficient estimates to at least 4…

3. People lose muscle mass as they age. Suppose a person lost 7% of their muscle mass between ages 50 and 60 (based on what they had at age 50) and 8% of their muscle mass from 60 to 70 (based on what they had at age 60). What percentage of the muscle mass that they had at age 50 have they lost by age 70? The following approach is INCORRECT! Explain why. The person lost 1% and then lost 8%. Since 1% + 8% =15%, they lost 15%. Explanation: Work: Answer the question, supporting your answer with work.

In North America, between 100 million and 1 billion birds die each year by crashing into windows on buildings, more than any other human-related cause. This figure represents up to 5% of all birds in the area. One possible solution is to construct windows angled downward slightly, so that they reflect the ground rather than an image of the sky to a flying bird. An experiment by Klem et al. (2004) compared the number of birds that died as a result of vertical windows, windows angled 20 degrees off vertical, and windows angled 40 degrees off vertical. The angles were randomly assigned with equal probability to six windows and changed daily; assume for this exercise that windows and window locations were identical in every respect except angle. Over the course of the experiment, 30 birds were killed by windows in the vertical orientation, 15 were killed by windows set at 20 degrees off vertical, and 8 were killed by windows set at 40 degrees off vertical. . Clearly state an appropriate…

Rivers in North Carolina contain small concentrations of mercury that can accumulate in fish over their lifetimes. The concentration of mercury in fish tissue can be obtained by catching fish and sending samples to a lab for analysis. A study was conducted on fish from the Waccamaw and Lumber Rivers to investigate mercury levels in tissues of largemouth bass. At several stations along each river a group of fish were caught, weighed and measured; in addition a filet from each fish was sent to a lab so that the tissue concentration of mercury could be determined. In all, 171 fish were caught at 15 different research stations along the Waccamaw and Lumber Rivers. Data from fish caught at one of these stations is shown in the followinng table: length weight 1616 47.0 48.7 1862 2855 55.7 45.2 1199 1320 44.7 1225 43.8 870 38.5 1455 45.8 1220 44.0 1033 40.4 Compute the correlation between length and weight for these fish. (Assume the correlation conditions have been satisfied and round your…

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In North America, between 100 million and 1 billion birds die each year by crashing into windows on buildings, more than any other human-related cause. This figure represents up to 5% of all birds in the area. One possible solution is to construct windows angled downward slightly so that they reflect the ground rather than an image of the sky to a flying bird. An experiment by Klem et al. (2004) compared the number of birds that died as a result of vertical windows, windows angled 20 degrees off vertical, and windows angled 40 degrees off vertical. The angles were randomly assigned with equal probability to six windows and changed daily; assume for this exercise that windows and window locations were identical in every respect except angle. Over the course of the experiment, 30 birds were killed by windows in the vertical orientation, 15 were killed by windows set at 20 degrees off vertical, and 8 were killed by windows set at 40 degrees off vertical.  a. Clearly state an appropriate…

In a recent survey, 72% of post-secondary graduates indicated that they expected to earn at least $6000/month by the time they were ready to retire. The survey is considered accurate within ±5.2%, 19 times in 20. If the graduating class that participated in this survey contained 2100 students, what is the lower and upper estimate of the number of students who expect to earn at least $600/month by the time they are ready to retire? Select one: O a. 1403 to 1621 О Б. 19 toо 20 C. 66.8 to 77.2 O d. 95%