A mobile computer network consists of a number of computers (called nodes) that communicate with each other while moving throughout a region. A node that is out of transmission range of the other nodes, so that it is unable to communicate, is said to be partitioned. In studies carried out at the Colorado School of Mines, S. Kurkowski found that in a network containing 186 nodes in which destinations were chosen at random from a uniform distribution, 19 nodes were partitioned. J. Norman found that in a network containing 169 nodes whose movements mimicked those on a college campus, 30 nodes were partitioned. Let px represent the population proportion of partitioned nodes in the network that mimicked those on a college campus and let py represent the population proportion of partitioned nodes in the network whose destinations were chosen at random. Find a 99% confidence interval for the difference px- py. Round the answers to four decimal places. The 99% confidence interval is

A market research group is interested in estimating the market share of three airline companies, A, B and C, operating on a particular flight path. These three airlines are the only companies operating on this route. Airline B claim that they have 50% of the business with the remaining percentage shared equally amongst airlines A and C, i.e. 25% each. The market research group decide to carry out an independent study and question a random sample of 97 people visiting an airport on a particular day. Each person was given price, timetables and service details of flights on this route for each of the three airlines. Provided with this information they were asked to select their airline of choice.The survey revealed the following observed frequencies Airline A - 26 Aurline B - 49 Airline C - 22 Test if there is any evidence to suggest that the airline's claim is incorrect, at significance level α = 0.05. Complete the test by answering the following questions : Which of the following is the…

An ecological study was carried out to assess the rates of vegetation growth at four marshy underdeveloped locations and to determine the reason of any discrepancies that were identified. A portion of the research entailed measuring the leaf lengths of a certain plant species on a predetermined date in May. There are six plants were chosen at random from each of the four sites to be utilized in the comparison. The leaf length per plant is represented in the table (in centimeters). Do the data provide enough evidence to suggest a difference? in average leaf length between the four locations? Use a level of significance of 0.05.An ecological study was carried out to assess the rates of vegetation growth at four marshy underdeveloped locations and to determine the reason of any discrepancies that were identified. A portion of the research entailed measuring the leaf lengths of a certain plant species on a predetermined date in May. There are six plants were chosen at random from each of…

a researcher in a large organisation wishes to study sickness absence among its employees. the organisation has a large number of branches. each keeps its records of its sickness leave.after a sample was collected it became apparent that the branches fell into three natural groups in terms of sales small, medium and large.from the data of all the branches the researcher found that 210 randomly selected staff 90 worked in small branches 36 in medium branches and the rest worked in large branches. in total 96 of the selected staff had no sickness day off of which 52 worked in small branches and 29 worked in large branches. form a table showing this information clearlya researcher in a large organisation wishes to study sickness absence among its employees. the organisation has a large number of branches. each keeps its records of its sickness leave.after a sample was collected it became apparent that the branches fell into three natural groups in terms of sales small, medium and…

A researcher is conducting an experimental study on the effect of aspirin on heart attack risk. In order to assign who will receive aspirin and who will receive a placebo, she first divides her study into three age groups (18-29, 30-49, and 50 or older). She then randomly assigns individuals within these age groups to either receive aspirin or the placebo. This is an example of a cluster ?

A researcher is interested in factors related to academic performance of students.  She hypothesized that for undergraduate students, there is an association between academic majors (STEM, Business, Education, Nursing) and amount of time spent studying each week (less than 3 days, 3 to 6 days, everyday).  To test her hypothesis, she randomly selected 1000 undergraduate students from various colleges/universities in Texas, and then classified each participant according to their major and amount of study time each week.  For her study, she found test-statistic of 23.75 and a p-value of 0.0006.  Using this information, fill in the necessary information below for her test. Distribution used:    a. chi-square distribution, 3 degrees of freedom   b. chi-square distribution, 4 degrees of freedom   c. chi-square distribution, 6 degrees of freedom   d. chi-square distribution, 12 degrees of freedom

An experiment was conducted to compare the effectiveness of four training programs, namely, A, B, C, and D in training assemblers of a piece of electronic equipment. Twenty employees were randomly selected and assigned to each program, that is, five employees per program. After completion of the training courses, each person was required to assemble four pieces of equipment, and the length of time (in secs) to complete the assembly was recorded. The summary of the data gathered is recorded in the table. At α=0.10, test for the hypothesis that the assembly times for people trained are the same for the four programs.   A B C D x̄ 62.46 51.00 63.47 60.57 s 4.13 4.03 4.49 4.60 n 5 5 5 5   Pairwise Comparison Test 1 Given the hypotheses: H0:μ1=μ4  ; Ha:μ1≠μ4   Compute for the Tukey's q-statistic. Round off to the nearest hundredths: _________________ Given the hypotheses: H0:μ1=μ4;      Ha:μ1≠μ4   What is the appropriate conclusion based on the computed q-statistic?…

An experiment was conducted to compare the effectiveness of four training programs, namely, A, B, C, and D in training assemblers of a piece of electronic equipment. Twenty employees were randomly selected and assigned to each program, that is, five employees per program. After completion of the training courses, each person was required to assemble four pieces of equipment, and the length of time (in secs) to complete the assembly was recorded. The summary of the data gathered is recorded in the table. At α=0.10, test for the hypothesis that the assembly times for people trained are the same for the four programs.   A B C D x̄ 62.46 51.00 63.47 60.57 s 4.13 4.03 4.49 4.60 n 5 5 5 5   1. What is the null and alternative hypothesis? 2. In the decision rule: Reject H0 if Fc>F0.10,(A,B)=C .Otherwise, fail to reject H0.  What is the value for df for treatments, A?   What is the value for df for error, B?   What is the critical value, C?  3. Decision for the ANOVA…

An experiment was conducted to compare the effectiveness of four training programs, namely, A, B, C, and D in training assemblers of a piece of electronic equipment. Twenty employees were randomly selected and assigned to each program, that is, five employees per program. After completion of the training courses, each person was required to assemble four pieces of equipment, and the length of time (in secs) to complete the assembly was recorded. The summary of the data gathered is recorded in the table. At α=0.10, test for the hypothesis that the assembly times for people trained are the same for the four programs.   A B C D x̄ 62.46 51.00 63.47 60.57 s 4.13 4.03 4.49 4.60 n 5 5 5 5   Suppose it makes sense to conduct a post-hoc analysis. We will use Tukey's test to make pairwise comparisons between means. The decision rule for Tukey's test would be as follows: "Reject H0 if |qc|>q0.10,K,L=M . Otherwise, fail to reject H0." 1. What is the value for the number of…

Television sets are given a final inspection following assembly. Three types of defects are identified, critical, major, and minor defects, by a mail-order house. Data are analyzed with the following results. Sets having no 75% defects Sets having only 2% critical defects Sets having only 5% major defects Sets having only 7% minor defects Sets having only 3% critical and major defects Sets having only 4% critical and minor defects Sets having only 3% minor and major defects Sets having all 1% three types of defects What is the probability that a randomly selected set has a critical or major defeca? OA. 0.10 OB. 0.35 OC. 0.25 OD. 0.01 OE. 0.30