Exam 19: Questions that Involve Online Topics

Which of the following is an assumption required by the Analysis of Means (ANOM)?

TABLE 16-1 Given below are the average prices for three types of energy products for five consecutive years. -Referring to Table 16-1, what is the Paasche price index for the group of three energy items in year 5 for a family that consumed 13 units of electricity, 26 units of natural gas and 235 units of fuel oil in year 5 using year 1 as the base year?

Using the hat matrix elements hᵢ to determine influential points in a multiple regression model with k independent variable and n observations, Xᵢ is an influential point if

TABLE 7-2 According to a survey, only 15% of customers who visited the website of a major retail store made a purchase. Random samples of size 50 are selected from a population of 900. Use the finite population correction factor. -Referring to Table 7-2, 90% of the samples will have more than what percentage of customers who will make a purchase after visiting the website?

TABLE 8-2 A wealthy real estate investor wants to decide whether it is a good investment to build a high-end shopping complex in a suburban county near Chicago. His main concern is the total market value of the 3,605 houses in the suburban county. He commissioned a statistical consulting group to take a sample of 200 houses and obtained a sample mean market price of $225,000 and a sample standard deviation of $38,700. The consulting group also found out that the mean differences between market prices and appraised prices was $125,000 with a standard deviation of $3,400. Also the proportion of houses in the sample that are appraised for higher than the market prices is 0.24. -Referring to Table 8-2, what will be the 90% confidence interval for the mean market price of the houses in the suburban county constructed by the consulting group?

To determine the probability of getting more than 3 events of interest in a binomial distribution, you will find the area under the normal curve for X = 3.5 and above.

The base period should be recent so that a price index is not severely affected by change in technology, and consumer attitudes and habits.

A buyer for a manufacturing plant suspects that his primary supplier of raw materials is overcharging. In order to determine if his suspicion is correct, he contacts a second supplier and asks for the prices on various identical materials. He wants to compare these prices with those of his primary supplier. He collected data on 6 different materials from both suppliers. He suspects that the differences are not normally distributed. Which of the following tests will be the most appropriate?

TABLE 9-1 A manufacturer produces light bulbs that have a mean life of at least 500 hours when the production process is working properly. Based on past experience, the population standard deviation is 50 hours and the light bulb life is normally distributed. The operations manager stops the production process if there is evidence that the population mean light bulb life is below 500 hours. -Referring to Table 9-1, if you select a sample of 100 light bulbs and are willing to have a level of significance of 0.05, the probability of the operations manager not stopping the process when the process is in fact working properly and is in fact below 500 hours is ________.

A company that manufactures designer jeans is contemplating whether to increase its advertising budget by $1 million for next year. If the expanded advertising campaign is successful, the company expects sales to increase by $1.6 million next year. If the advertising campaign fails, the company expects sales to increase by only $400,000 next year. If the advertising budget is not increased, the company expects sales to increase by $200,000. Identify the events in this decision-making problem.

TABLE 6-1 A company has 125 personal computers. The probability that any one of them will require repair on a given day is 0.15. -Referring to Table 6-1, which of the following is one of the properties required so that the binomial distribution can be used to compute the probability that no more than 2 computers will require repair on a given day?

A simple price index tracks the price of a group of commodities at a given period of time to the price paid for that group of commodities at a particular point of time in the past.

TABLE 8-2 A wealthy real estate investor wants to decide whether it is a good investment to build a high-end shopping complex in a suburban county near Chicago. His main concern is the total market value of the 3,605 houses in the suburban county. He commissioned a statistical consulting group to take a sample of 200 houses and obtained a sample mean market price of $225,000 and a sample standard deviation of $38,700. The consulting group also found out that the mean differences between market prices and appraised prices was $125,000 with a standard deviation of $3,400. Also the proportion of houses in the sample that are appraised for higher than the market prices is 0.24. -Referring to Table 8-2, what will be the 90% confidence interval for the population proportion of houses that will be appraised for higher than the market prices?

TABLE 19-6 A student wanted to find out the optimal strategy to study for a Business Statistics exam. He constructed the following payoff table based on the mean amount of time he needed to study every week for the course and the degree of difficulty of the exam. From the information that he gathered from students who had taken the course, he concluded that there was a 40% probability that the exam would be easy. -Referring to Table 19-6, the optimal strategy using the return-to-risk ratio criterion is to study 8 hours per week on average for the exam.

To determine the probability of getting fewer than 3 events of interest in a binomial distribution, you will find the area under the normal curve for X = 3.5 and below.

TABLE 16-1 Given below are the average prices for three types of energy products for five consecutive years. -Referring to Table 16-1, what is the unweighted aggregate price index for the group of three energy items in year 3 using year 1 as the base year?

TABLE 6-1 A company has 125 personal computers. The probability that any one of them will require repair on a given day is 0.15. -Referring to Table 6-1 and assuming that the number of computers that requires repair on a given day follows a binomial distribution, compute the probability that there will be between 25 and 30 computers that require repair on a given day using a normal approximation.

TABLE 19-2 The following payoff matrix is given in dollars. -Referring to Table 19-2, the EMV for Action A is

As a general rule, one can use the normal distribution to approximate a binomial distribution whenever the sample size is at least 15.

TABLE 12-1 A perfume manufacturer is trying to choose between 2 magazine advertising layouts. An expensive layout would include a small package of the perfume. A cheaper layout would include a "scratch-and-sniff" sample of the product. The manufacturer would use the more expensive layout only if there is evidence that it would lead to a higher approval rate. The manufacturer presents both layouts to 5 groups and determines the approval rating from each group on both layouts. The data are given below. Use this to test whether the median difference in approval rating is different from zero in favor of the more expensive layout with a level of significance of 0.05. -Referring to Table 12-1, what is the rank of the absolute difference for the last pair of observations?