Exam 19: Questions that Involve Online Topics

TABLE 8-1 A random sample of 100 stores from a large chain of 500 garden supply stores was selected to determine the mean number of lawnmowers sold at an end-of-season clearance sale. The sample results indicated a mean of 6 and a standard deviation of 2 lawnmowers sold. A 95% confidence interval (5.623 to 6.377) was established based on these results. -Referring to Table 8-1, if the population had consisted of 1,000 stores, the confidence interval estimate of the mean with finite population correction would have been wider in range.

The changes in the price of the least consumed commodities are overly influential in a weighted aggregate price index.

TABLE 9-2 An appliance manufacturer claims to have developed a compact microwave oven that consumes a population mean of no more than 250 W. From previous studies, it is believed that power consumption for microwave ovens is normally distributed with a population standard deviation of 15 W. If there is evidence that the population mean consumption is greater than 250 W, the manufacturer will be unable to make the claim. -Referring to Table 9-2, if you select a sample of 20 compact microwave ovens and are willing to have a level of significance of 0.01, the probability of making a Type II error is ________ if the mean power consumption of all such microwave ovens is in fact 248 W.

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 0.01, the probability of the operations manager not stopping the process if the population mean bulb life is 510 hours is ________.

TABLE 19-1 The following payoff table shows profits associated with a set of 3 alternatives under 2 possible states of nature. -Referring to Table 19-1, if the probability of S1 is 0.5, then the EVPI for the payoff table is

TABLE 19-1 The following payoff table shows profits associated with a set of 3 alternatives under 2 possible states of nature. -Referring to Table 19-1, if the probability of S1 is 0.2 and S2 is 0.8, then the expected monetary value of A1 is

The finite population correction factor is

TABLE 16-2 Given below are the prices of a basket of four food items from 2006 to 2010. -Referring to Table 16-2, what is the Laspeyres price index for the basket of four food items in 2009 that consisted of 50 bushels of wheat, 30 bushels of corn, 40 bushels of soybeans and 80 hundredweight of milk in 2006 using 2006 as the base year?

The Paasche price index is a form of unweighted aggregate price index.

Only when all three of the hat matrix elements hᵢ, the Studentized deleted residuals tᵢ and the Cook's distance statistic Dᵢ reveal consistent result should an observation be removed from the regression analysis.

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 maximax criterion is to study 16 hours per week on average for the exam.

In a local cellular phone area, company A accounts for 60% of the cellular phone market, while company B accounts for the remaining 40% of the market. Of the cellular calls made with company A, 1% of the calls will have some sort of interference, while 2% of the cellular calls with company B will have interference. If a cellular call is selected at random, the probability that it will have interference is

TABLE 19-1 The following payoff table shows profits associated with a set of 3 alternatives under 2 possible states of nature. -Referring to Table 19-1, if the probability of S1 is 0.5, then the return to risk ratio for A1 is

TABLE 7-1 Times spent studying by students in the week before final exams follow a normal distribution with standard deviation 8 hours. A random sample of 4 students was taken from a population of 50 in order to estimate the mean study time for the population of all students. Use the finite population correction. -Referring to Table 7-1, what is the standard error of all the sample means?

TABLE 9-3 A drug company is considering marketing a new local anesthetic. The effective time of the anesthetic the drug company is currently producing has a normal distribution with a mean of 7.4 minutes with a standard deviation of 1.2 minutes. The chemistry of the new anesthetic is such that the effective time should be normally distributed with the same standard deviation. The company will market the new local anesthetic as being better if there is evidence that the population mean effective time is greater than the 7.4 minutes of the current local anesthetic. -Referring to Table 9-3, if you select a sample of 25 new local anesthetics and are willing to have a level of significance of 0.01, the probability of the company incorrectly marketing the new local anesthetic when its population mean effective time is not greater than the 7.4 minutes is ________.

TABLE 7-1 Times spent studying by students in the week before final exams follow a normal distribution with standard deviation 8 hours. A random sample of 4 students was taken from a population of 50 in order to estimate the mean study time for the population of all students. Use the finite population correction. -Referring to Table 7-1, what is the probability that the sample mean differs from the population mean by less than 2 hours?

At Eastern University, 60% of the students are from suburban areas, 30% are from rural areas, and 10% are from urban areas. Of the students from the suburban areas, 60% are nonbusiness majors. Of the students from the rural areas, 70% are nonbusiness majors. Of the students from the urban areas, 90% are nonbusiness majors. The probability that a randomly selected student is a business major is

You have 5 stocks in your investment portfolio. You want to keep track of your portfolio's performance over the last 2 years. You have data on each of the stock's average price and the number of shares of each stock for every day of the last 2 years. Which of the following would be the most appropriate analysis to perform?

Blossom's Flowers purchases roses for sale for Valentine's Day. The roses are purchased for $10 a dozen and are sold for $20 a dozen. Any roses not sold on Valentine's Day can be sold for $5 per dozen. The owner will purchase 1 of 3 amounts of roses for Valentine's Day: 100, 200, or 400 dozen roses. The number of alternatives for the payoff table is

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 total market price of the houses in the suburban county constructed by the consulting group?