Partial preview of the text
Download COMM 214 Business Analytics Final Mock 2 study guide 2025 Concordia University and more Exams Effective Business Communication in PDF only on Docsity!
Question 1 The crop yield for a specified farm in a selected year is measured in the amount of crop produced per acre. It is known that a normal distribution can be used to characterize crop yields over time. Based on historical data it is projected that next summer's crop yield, for a particular regional farm, will be 1500 pounds per acre and a standard deviation of 250. Studies indicate that a farm will be profitable if it produces at least 1600 pounds per acre. a. What is the probability that the farm will lose money next summer? b. Assume that farming conditions remain unchanged for the next two years. That is, the distribution of crop yields remain the same and the chances of making a profit or losing do not change, and crop yields are independent of previous year’s conditions. What is the probability that the farm will lose money for two straight years? c. What is the probability that the yields per acre will fall within two standard deviations of 1500 pounds per acre? COMM 214 - Business Analytics Question 2 ZUBRAK is an auto repair shop, as part of its quality efforts, the company wishes to estimate the mean time its customers wait for their car to be repaired. A sample of 16 customers was taken and the average waiting time was found to be 7 hours and 45 minutes, with a standard deviation of 0.68 hours. a) Compute the 95% confidence interval for the mean waiting time of customers at ZUBRAK. b) How many additional customers should be sampled if the company wishes to estimate waiting time to within 12 minutes? COMM 214 - Business Analytics Question 3 A marketing agency advertises an introductory offer, through which new members are entitled to receive an initial package at a nominal price with no obligation to purchase more. The agency estimates that this promotion will be profitable if the new members buy, on average, at least 20 items during the following year. A random sample of 100 records of members attracted by this offer showed a mean purchase in the next year of 20.98 items and a standard deviation of 1.4 items. a. Can you conclude that the promotion was profitable at a .05 level of significance? b. What is the p-value of the above test? e. According to your answer in part a), would you be subject to making a Type | or a Type Il error? Explain. a. If the agency wants to reduce the standard error (used in part a) by half, how many records should be sampled? COMM 214 - Business Analytics Question 5 ZUBRAK Inc. is a computer firm specializing in Web designs. Since ZUBRAK uses its own special web page design software, all newly hired employees have to go through a training course regardless of their work experience in computing. The vice-president of personnel is skeptical about paying a higher salary to hire more experienced people since they have to be retrained. For each of 15 randomly selected new employees, she obtained data on the employee's score in web page design skill Y (after the training course) and also he number of months of computer related work experience X at the time of hiring. Part of the data along with sums, sums of squares and some relevant statistic are given below. Employel 1] 2] 3].]. 7. [13] 14] 75 e Xi 19/10; 12| . |. | . | 18/15/14 Yi 81} 66; 70; . | . | . | 88) 78| 73 X = 15.733,Y = 76.4667, XW —Y)2 = 9376.22, SSE = 188.03, Ss, = 0.2961 Suppose that a simple linear regression model is appropriate for analyzing the above data and the least squares fit is obtained as Y = 49.579 + 1.709X: a. At 5% significance level, is there sufficient evidence that design skill is positively related to computer related work experience? Interpret the result in the context of the problem. b. What proportion of the variation of design skill scores is accounted for by computer related work experience? Interpret the result in the context of the problem. COMM 214 - Business Analytics Question 5 c. Find a 95% prediction interval for design skill score of an employee with 15 months of computer related work experience. Interpret the result in the context of the problem. COMM 214 - Business Analytics B) Calculate the coefficient of determination. ©) Which variable is the strongest? D) Test with a 5% level of significance is there is a significant relationship between the shipping cost and sales. COMM 214 - Business Analytics £) What are the sales when the shipping cost is $2/unit, the print advertising budget is $5,000, the electronic media advertising budget is $10,000 and there is a 5% rebate. COMM 214 Business Analytics Final Mock 2 study guide 2025 Concordia UniversityCOMM 214 Business Analytics Final 
