11. A testing organization gathered some data on the lifetime of a crucial component of each of two brands obtained from random samples of the component placed on an accelerated life test. There have been reports of failures of a particular brand (labeled as Brand A) of flat panel LCD television sets. The following table provides the data on estimated lifetimes (in months). Brand A B Lifetime of Lifetime of component component 32 41 25.5 39 Lifetime of component 40.5 36 Lifetime of component 31 47 Lifetime of component 45 35 Lifetime of component 29 34 Lifetime of component 37 48 Use the Wilconxon signed-rank test to determine if the component lifetime of Brand A is shorter than the lifetime for Brand B. Perform on the 5% level (a = 0.05). What is your conclusion? (15p) Lifetime of component 39.5 44

Old Faithful is a geyser located in Yellowstone National Park in Wyoming, USA. Millions of travelers come from afar to witness Old Faithful's eruptions each year. Travelers to Yellowstone are told that Old Faithful is expected to erupt, on average, every 7272 minutes, but park scientists suspect that this average is incorrect.   To investigate, the scientists determine the waiting time until the next eruption for a random sample of 272272 Old Faithful eruptions. The waiting times have a mean of 70.897 minutes and a standard deviation of 13.595 minutes. You will use these data to carry out a significance test at the ?α = 0.05 level.

(b) In various places in this module, data on the silver content of coins minted in the reign of the twelfth-century Byzantine king Manuel I Comnenus have been considered. The full dataset is in the Minitab file coins.mwx. The dataset includes, among others, the values of the silver content of nine coins from the first coinage (variable Coin1) and seven from the fourth coinage (variable Coin4) which was produced a number of years later. (For the purposes of this question, you can ignore the variables Coin2 and Coin3.) In particular, in Activity 8 and Exercise 2 of Computer Book B, it was argued that the silver contents in both the first and the fourth coinages can be assumed to be normally distributed. The question of interest is whether there were differences in the silver content of coins minted early and late in Manuel’s reign. You are about to investigate this question using a two-sample t-interval. (i) Using Minitab, find either the sample standard deviations of the two variables…

number 9

9.2.6 The British Department of Transportation studied to see if people avoid driving on Friday the 13th.   They did a traffic count on a Friday and then again on a Friday the 13th at the same two locations ("Friday the 13th," 2013).  The data for each location on the two different dates is in table #9.2.6.  Estimate the mean difference in traffic count between the 6th and the 13th using a 90% level. Table #9.2.6: Traffic Count Dates 6th 13th 1990, July 139246 138548 1990, July 134012 132908 1991, September 137055 136018 1991, September 133732 131843 1991, December 123552 121641 1991, December 121139 118723 1992, March 128293 125532 1992, March 124631 120249 1992, November 124609 122770 1992, November 117584 117263

Chicken farming is a multi-billion dollar industry, and any methods that increase the growth rate of young chicks can reduce consumer costs while increasing company profits, possibly by millions of dollars. An experiment was conducted to measure and compare the effectiveness of various feed supplements on the growth rate of chickens. Newly hatched chicks were randomly allocated into six groups, and each group was given a different feed supplement. Below are some summary statistics from this data set showing the distribution of weights by feed type.     Mean SD Sample Size casein 323.58 64.43 12 horsebean 160.20 38.63 10 linseed 218.75 52.24 12 meatmeal 276.91 64.90 11 soybean 246.43 54.13 14 sunflower 328.92 48.84 12 (a) Do these data provide strong evidence that the average weights of chickens that were fed lineseed and horsebean are different? Use a 5% significance level.Hint: We are interested in the difference: lineseed-horsebean Test Statistic: _______…

As a hospital administrator of a large hospital, you areconcerned with the absenteeism among nurses’ aides. Theissue has been raised by registered nurses, who feel theyoften have to perform work normally done by their aides.To get the facts, absenteeism data were gathered for the last3 weeks, which is considered a representative period for future conditions. After taking random samples of 64 personnelfiles each day, the following data were produced: Because your assessment of absenteeism is likely to comeunder careful scrutiny, you would like a type I error of only1 percent. You want to be sure to identify any instances of unusual absences. If some are present, you will have to explorethem on behalf of the registered nurses. a. Design a p-chart.b. Based on your p-chart and the data from the last 3 weeks,what can you conclude about the absenteeism of nurses’aides?

According to the National Health and Nutrition Examination Survey (NHANES) sponsored by the U.S. government, a random sample of 712 males between 20 and 29 years of age and a random sample of 1,001 males over the age of 75 were chosen and the weight of each of the males were recorded (in kg). Do the data provide evidence that the younger male population weighs more (on average) than the older male population? Use “Y” for ages 20-29 and “S” for ages 75+. It was found that x̅Y=83.4, sY=18.7, x̅S=78.5, and sS=19.0.   a)Suppose the test statistic is t = 2.398. What is the associated p-value? Group of answer choices 0.001 < p-value < 0.002 0.005 < p-value < 0.01 0.01 < p-value < 0.02 0.0005 < p-value < 0.001   b) Suppose the p-value is 0.02 < p-value < 0.04. At α = 0.10 what is the appropriate conclusion to make? Group of answer choices Fail to reject H0 and conclude that the mean weight of all males ages 20-29 is greater than the mean weight of all…

According to the National Health and Nutrition Examination Survey (NHANES) sponsored by the U.S. government, a random sample of 712 males between 20 and 29 years of age and a random sample of 1,001 males over the age of 75 were chosen and the weight of each of the males were recorded (in kg). Do the data provide evidence that the younger male population weighs more (on average) than the older male population? Use “Y” for ages 20-29 and “S” for ages 75+. It was found that x̅Y=83.4, sY=18.7, x̅S=78.5, and sS=19.0.   a) Is the normality condition met for this test? (see picture) No, since the histograms show skewness and outliers .   Yes, since both sample sizes are larger than 30. No, since both sample sizes, nY and nS, are less than 30. Yes, since it was stated that the two populations are normally distributed.   b)What are the correct degrees of freedom for this test? Group of answer choices 999 1000 1712 1711 711

According to the National Health and Nutrition Examination Survey (NHANES) sponsored by the U.S. government, a random sample of 712 males between 20 and 29 years of age and a random sample of 1,001 males over the age of 75 were chosen and the weight of each of the males were recorded (in kg). Do the data provide evidence that the younger male population weighs more (on average) than the older male population? Use “Y” for ages 20-29 and “S” for ages 75+. It was found that x̅Y=83.4, sY=18.7, x̅S=78.5, and sS=19.0. A) What are the correct null and alternative hypotheses? B)What is the parameter of interest?   The difference between the mean weight of all males ages 20-29 and the mean weight of all males ages 75+ The mean weight (in kg) The difference between the mean weight of the sample of males ages 20-29 and the mean weight of the sample of males ages 75+ The mean difference between the weights of males ages 20-29 and males ages 75+   c)Is the randomness condition met for…