An emergency cell phone charger requires you to turn a small crank in order to create the energy needed to recharge the phone’s battery. If you turn the crank 120 times per minute, the total number r of revolutions that you turn the crank is given by r = 120t where t is the time (in minutes) spent turning the crank. a. Graph the function and identify its domain and range. b. Identify the domain and range if you stop turning the crank after 4 minutes. Explain how this affects the appearance of the graph.

Hos pitals typically req uire backup generators to provide electricity in the event of a power outage. Assume that emergency backup generato rs fai l 22% of the times when they are needed (based on data from Arshad Mansoor, senior vice president with the Electric Power Research In stitute). A hospital has two backup generators so that power is avail able if one of them fails during a power outage. Find the probability that both generators fail during a power outage.

Study of why EMS workers leave the job. A study of fulltime emergency medical service (EMS) workers published in the Journal of Allied Health (Fall 2011) found that only about $3 \%$ leave their job in order to retire. (See Exercise $3.45$, p. 158.) Assume that the true proportion of all fulltime EMS workers who leave their job in order to retire is $p=.03$. In a random sample of 1,000 full-time EMS workers, let $\hat{p}$ represent the proportion who leave their job in order to retire. Describe the properties of the sampling distribution of $\hat{p}$.

You are working in the emergency department (ED) of a community hospital when the ambulance arrives with A.N., an $18$-year-old woman who was caught in a house fire. She was sleeping when the fire started and managed to make her way out of the house through thick smoke. The emergency medical system crew initiated humidified oxygen at $15 \mathrm{~L} / \mathrm{min}$ per nonrebreather mask and started a $16$-gauge IV with lactated Ringer's solution. On arrival to the ED, her vital signs are $100/66, 125, 34$, $\mathrm{SaO}_2 93 \%$. An additional $16$-gauge IV is inserted. She appears anxious and in pain.

Eighteen hours after the injury, the NAP reports these vital signs for A.N. and states that the urine output for the past hour was $20$ mL.

$$\begin{aligned} &\text { Vital Signs }\\ &\begin{array}{ll} \text { Blood pressure } & 90 / 50 \mathrm{~mm} \mathrm{Hg} \\ \text { Heart rate } & 110 \text { beats } / \mathrm{min} \\ \text { Respiratory rate } & 24 \text { breaths } / \mathrm{min} \end{array} \end{aligned}$$

What treatment do you anticipate?

Doctors treated a patient at an emergency room from 2:00 P.M. to 7:00 P.M. The patient’s blood oxygen level L (in percent) during this time period can be modeled by $L=-0.270 t^{2}+3.59 t+83.1, \quad 2 \leq t \leq 7$ where t represents the time of day, with t=2 corresponding to 2:00 P.M. Use the model to estimate the time (rounded to the nearest hour) when the patient’s blood oxygen level was 93%.

A patient is evaluated in the emergency department after causing an automobile accident while being under the influence of alcohol. While assessing the patient, which statement would be the most therapeutic?

1. “Why did you drive after you had been drinking?”
2. “We have multiple patients to see tonight as a result of this accident.”
3. “Tell me what happened before, during, and after the automobile accident tonight.”
4. “It will be okay. No one was seriously hurt in the accident.”

Large stadiums rely on backup generators to provide electricity in the event of a power failure. Assume that emergency backup generators fail 22% of the times when they are needed (based on data from Arshad Mansoor, senior vice president with the Electric Power Research Institute). A stadium has three backup generators so that power is available if at least one of them works in a power failure. Find the probability of having at least one of the backup generators working given that a power failure has occurred. Does the result appear to be adequate for the stadium's needs?

Study of why EMS workers leave the job. A study of fulltime emergency medical service (EMS) workers published in the Journal of Allied Health (Fall 2011) found that only about 3% leave their job in order to retire. (See Exercise $3.45$, p. 158.) Assume that the true proportion of all fulltime EMS workers who leave their job in order to retire is $p=.03$. In a random sample of 1,000 full-time EMS workers, let $\hat{p}$ represent the proportion who leave their job in order to retire. Compute $P(\hat{p}<.05)$. Interpret this result.

The temperature T (in degrees Fahrenheit) of a patient t hours after arriving at the emergency room of a hospital at 10:00 P.M. is given by $T(t)=98.6+4 \cos \frac{\pi t}{36}, \quad 0 \leq t \leq 18$. Find the patient’s temperature at (a) 10:00 P.M., (b) 4:00 A.M., and (c) 10:00 A.M. (d) At what time do you expect the patient’s temperature to return to normal? Explain your reasoning.

A social agency provides emergency food and shelter to two groups of clients. The first group has x clients who need an average of $300 for emergencies, and the second group has y clients who need an average of$200 for emergencies. The agency has $100,000 to spend for these two groups.

a. Write an equation that describes the maximum number of clients who can be served with the$100,000.

b. If the first group has twice as many clients as the second group, how many clients are in each group if all the money is spent?

Define Type I and Type II error for each scenario, and identify the cost(s) of each type of error.

Approaching O'Hare for landing, a British Air flight from London has been in a holding pattern for $45$ minutes due to bad weather. Landing is expected within $15$ minutes. The flight crew could declare an emergency and land immediately, but an FAA investigation would be launched and other flights might be endangered. The null hypothesis is that there is enough fuel to stay aloft for $15$ more minutes.

The frequency table summarizes the distribution of time that 140 patients at the emergency room of a small-city hospital waited to receive medical attention during the last month.

$$\begin{array}{lr} \hline \text { Waiting time } & \text { Frequency } \\ \hline \text { Less than } 10 \text { minutes } & 5 \\ \text { At least } 10 \text { but less than } 20 \text { minutes } & 24 \\ \text { At least } 20 \text { but less than } 30 \text { minutes } & 45 \\ \text { At least } 30 \text { but less than } 40 \text { minutes } & 38 \\ \text { At least } 40 \text { but less than } 50 \text { minutes } & 19 \\ \text { At least } 50 \text { but less than } 60 \text { minutes } & 7 \\ \text { At least } 60 \text { but less than } 70 \text { minutes } & 2 \\ \hline \end{array}$$

Which of the following represents possible values for the median and IQR of waiting times for the emergency room last month? (a) median = 27 minutes and IQR = 15 minutes (b) median = 28 minutes and IQR = 25 minutes (c) median = 31 minutes and IQR = 35 minutes (d) median = 35 minutes and IQR = 45 minutes (e) median = 45 minutes and IQR = 55 minutes

You are working in the emergency department (ED) of a community hospital when the ambulance arrives with A.N., an $18$-year-old woman who was caught in a house fire. She was sleeping when the fire started and managed to make her way out of the house through thick smoke. The emergency medical system crew initiated humidified oxygen at $15 \mathrm{~L} / \mathrm{min}$ per nonrebreather mask and started a $16$-gauge IV with lactated Ringer's solution. On arrival to the ED, her vital signs are $100/66, 125, 34$, $\mathrm{SaO}_2 93 \%$. An additional $16$-gauge IV is inserted. She appears anxious and in pain.

$$\begin{aligned} &\text { Laboratory Test Values }\\ &\begin{array}{ll} \text { Hgb } & 20 \mathrm{~g} / \mathrm{dL} \\ \text { Hct } & 51 \% \\ \mathrm{~K} & 4.9 \mathrm{mEq} / \mathrm{dL} \\ \mathrm{Na} & 133 \mathrm{mEq} / \mathrm{dL} \\ \mathrm{Cl} & 100 \mathrm{mEq} / \mathrm{dL} \\ \text { Glu } & 159 \mathrm{mg} / \mathrm{dL} \\ \text { BUN } & 28 \mathrm{mg} / \mathrm{dL} \\ \text { Cre } & 1.0 \mathrm{mg} / \mathrm{dL} \end{array} \end{aligned}$$

Interpret A.N.'s laboratory results.

The frequency distribution shows the number of medical tests conducted on 30 randomly selected emergency room patients.

If a patient is selected at random, find these probabilities:

a. The patient had exactly 3 tests done. b. The patient had at most 2 tests done. c. The patient has 1 or 2 tests done. d. The patient had fewer than 3 tests done. e. The patient had at least 3 tests done.