According to Global Research News (Mar. 4, 2014), one-fourth of all rough diamonds produced in the world are blood diamonds. (Any diamond that is mined in a war zone - often by children - in order to finance a warlord's activity, an insurgency, or an invading army's effort is considered a blood diamond.) Also, 90% of the world's rough diamonds are processed in Surat, India, and of these diamonds, one-third are blood diamonds. Find the probability that a rough diamond is processed in Surat and is a blood diamond.

Ambulance response time. Geographical Analysis (Jan. 2010) presented a study of emergency medical service (EMS) ability to meet the demand for an ambulance. In one example, the researchers presented the following scenario. An ambulance station has one vehicle and two demand locations, A and B. The probability that the ambulance can travel to a location in under 8 minutes is $.58$ for location A and .42 for location B. The probability that the ambulance is busy at any point in time is $.3$. Find the probability that EMS can meet the demand for an ambulance at location A.

Crude oil biodegradation. Refer to the Journal of Petroleum Geology (April 2010) study of the environmental factors associated with biodegradation in crude oil reservoirs, Exercise $6.38$ (p. 326). Recall that 16 water specimens were randomly selected from various locations in a reservoir on the floor of a mine and that the amount of dioxide (milligrams/liter) - a measure of biodegradation-as well as presence of oil were determined for each specimen. These data are reproduced in the accompanying table. Conduct a test to determine if the true mean amount of dioxide present in water specimens that contained oil was less than 3 milligrams/liter. Use $\alpha=.10$.

Crude oil biodegradation. Refer to the Journal of Petroleum Geology (April 2010) study of the environmental factors associated with biodegradation in crude oil reservoirs, Exercise $2.29$ (p. 61). Recall that amount of dioxide (milligrams/liter) and presence/absence of crude oil was determined for each of 16 water specimens collected from a mine reservoir. The data are repeated in the accompanying table. Find the main dioxide level of the 16 water specimens. Interpret this value.

Crude oil biodegradation. Refer to the Journal of Petroleum Geology (April 2010) study of the environmental factors associated with biodegradation in crude oil reservoirs, Exercise $2.29$ (p. 61). One indicator of biodegradation is the level of dioxide in the water. Recall that 16 water specimens were randomly selected from various locations in a reservoir on the floor of a mine and the amount of dioxide (milligrams/liter) as well as presence of oil was determined for each specimen. These data are reproduced in the next table. Estimate the true mean amount of dioxide present in water specimens that contain oil using a $95 \%$ confidence interval. Give a practical interpretation of the interval.

It costs you $10 to draw a sample of size n = 1 and measure the attribute of interest. You have a budget of$1,200. a. Do you have sufficient funds to estimate the population mean for the attribute of interest with a 95% confidence interval 4 units in width? Assume that

$$\sigma = 12$$

b. If a 90% confidence level were used, would your answer to part a change? Explain.

It costs you $\$ 10$ to draw a sample of size $n=1$ and measure the attribute of interest. You have a budget of $\$ 1,500$. Do you have sufficient funds to estimate the population mean for the attribute of interest with a $95 \%$ confidence interval 5 units in width? Assume $\sigma=14$.

The day after Thanksgiving - called Black Friday-is one of the largest shopping days in the United States. Winthrop University researchers conducted interviews with a sample of 38 women shopping on Black Friday to gauge their shopping habits and reported the results in the International Journal of Retail and Distribution Management (Vol. 39, 2011). One question was "How many hours do you usually spend shopping on Black Friday?" Data for the 38 shoppers are listed in the accompanying table.
A retail store advertises that the true mean number of hours spent shopping on Black Friday is 5.5 hours. Should the store be sued for false advertising? Explain.

$$\begin{matrix} \text{6} & \text{6} & \text{4} & \text{4} & \text{3} & \text{16} & \text{4} & \text{4} & \text{5} & \text{6} & \text{6} & \text{5} & \text{5} & \text{4}\\ \text{6} & \text{5} & \text{6} & \text{4} & \text{5} & \text{4} & \text{4} & \text{4} & \text{7} & \text{12} & \text{5} & \text{8} & \text{6} & \text{10}\\ \text{5} & \text{8} & \text{8} & \text{3} & \text{3} & \text{8} & \text{5} & \text{6} & \text{10} & \text{11}\\ \end{matrix}$$

The day after Thanksgiving - called Black Friday-is one of the largest shopping days in the United States. Winthrop University researchers conducted interviews with a sample of 38 women shopping on Black Friday to gauge their shopping habits and reported the results in the International Journal of Retail and Distribution Management (Vol. 39, 2011). One question was "How many hours do you usually spend shopping on Black Friday?" Data for the 38 shoppers are listed in the accompanying table.
What is the quantitative variable of interest to the researchers?

$$\begin{matrix} \text{6} & \text{6} & \text{4} & \text{4} & \text{3} & \text{16} & \text{4} & \text{4} & \text{5} & \text{6} & \text{6} & \text{5} & \text{5} & \text{4}\\ \text{6} & \text{5} & \text{6} & \text{4} & \text{5} & \text{4} & \text{4} & \text{4} & \text{7} & \text{12} & \text{5} & \text{8} & \text{6} & \text{10}\\ \text{5} & \text{8} & \text{8} & \text{3} & \text{3} & \text{8} & \text{5} & \text{6} & \text{10} & \text{11}\\ \end{matrix}$$

The day after Thanksgiving - called Black Friday-is one of the largest shopping days in the United States. Winthrop University researchers conducted interviews with a sample of 38 women shopping on Black Friday to gauge their shopping habits and reported the results in the International Journal of Retail and Distribution Management (Vol. 39, 2011). One question was "How many hours do you usually spend shopping on Black Friday?" Data for the 38 shoppers are listed in the accompanying table. Describe the population of interest to the researchers.

$$\begin{matrix} \text{6} & \text{6} & \text{4} & \text{4} & \text{3} & \text{16} & \text{4} & \text{4} & \text{5} & \text{6} & \text{6} & \text{5} & \text{5} & \text{4}\\ \text{6} & \text{5} & \text{6} & \text{4} & \text{5} & \text{4} & \text{4} & \text{4} & \text{7} & \text{12} & \text{5} & \text{8} & \text{6} & \text{10}\\ \text{5} & \text{8} & \text{8} & \text{3} & \text{3} & \text{8} & \text{5} & \text{6} & \text{10} & \text{11}\\ \end{matrix}$$

The day after Thanksgiving - called Black Friday-is one of the largest shopping days in the United States. Winthrop University researchers conducted interviews with a sample of 38 women shopping on Black Friday to gauge their shopping habits and reported the results in the International Journal of Retail and Distribution Management (Vol. 39, 2011). One question was "How many hours do you usually spend shopping on Black Friday?" Data for the 38 shoppers are listed in the accompanying table. Use the information in the table to estimate the population mean number of hours spent shopping on Black Friday with a 95% confidence interval.

$$\begin{matrix} \text{6} & \text{6} & \text{4} & \text{4} & \text{3} & \text{16} & \text{4} & \text{4} & \text{5} & \text{6} & \text{6} & \text{5} & \text{5} & \text{4}\\ \text{6} & \text{5} & \text{6} & \text{4} & \text{5} & \text{4} & \text{4} & \text{4} & \text{7} & \text{12} & \text{5} & \text{8} & \text{6} & \text{10}\\ \text{5} & \text{8} & \text{8} & \text{3} & \text{3} & \text{8} & \text{5} & \text{6} & \text{10} & \text{11}\\ \end{matrix}$$

The day after Thanksgiving - called Black Friday-is one of the largest shopping days in the United States. Winthrop University researchers conducted interviews with a sample of 38 women shopping on Black Friday to gauge their shopping habits and reported the results in the International Journal of Retail and Distribution Management (Vol. 39, 2011). One question was "How many hours do you usually spend shopping on Black Friday?" Data for the 38 shoppers are listed in the accompanying table. Give a practical interpretation of the interval.

$$\begin{matrix} \text{6} & \text{6} & \text{4} & \text{4} & \text{3} & \text{16} & \text{4} & \text{4} & \text{5} & \text{6} & \text{6} & \text{5} & \text{5} & \text{4}\\ \text{6} & \text{5} & \text{6} & \text{4} & \text{5} & \text{4} & \text{4} & \text{4} & \text{7} & \text{12} & \text{5} & \text{8} & \text{6} & \text{10}\\ \text{5} & \text{8} & \text{8} & \text{3} & \text{3} & \text{8} & \text{5} & \text{6} & \text{10} & \text{11}\\ \end{matrix}$$

Global Foundries (GF), a privately held company that invests in companies producing essential components for high-volume data storage, is valued at $4.0 billion dollars. A computer company that wants to get into cloud computing is considering the purchase of GF, but because of the uncertain economy, it would prefer to purchase an option that will allow it to buy the company for up to 1 year from now at a cost of$4.3 billion. What is the maximum amount the company should be willing to pay for the option if its MARR is 9% per year?

Two deadly gases that can be present in fire smoke are hydrogen cyanide and carbon monoxide. Fire Engineering (Mar. 2013) reported the results of a survey of 244 firefighters conducted by the Fire Smoke Coalition. The purpose of the survey was to assess the base level of knowledge of firefighters regarding the use of gas detection devices at the scene of a fire. The survey revealed the following: Eighty percent of firefighters had no standard operating procedures (SOP) for detecting/monitoring hydrogen cyanide in fire smoke; 49% had no SOP for detecting/monitoring carbon monoxide in fire smoke. Assume that 94% of firefighters had no SOP for detecting either hydrogen cyanide or carbon monoxide in fire smoke. What is the probability that a firefighter has no SOP for detecting hydrogen cyanide and no SOP for detecting carbon monoxide in fire smoke?