The results of a 2013 Adobe Systems study on retail apps and buying habits reveal insights on perceptions and attitudes toward mobile shopping using retail apps and browsers, providing new direction for retailers to develop their digital publishing strategies. Increased consumer interest in using shopping applications means retailers must adapt to meet the rising expectations for specialized mobile shopping experiences. The results indicate that tablet users (55percent) are almost twice as likely as smartphone users (28 percent) to use their device to purchase products and services. The findings also reveal that retail and catalog apps are rapidly catching up to mobile browsers as a viable shopping channel: nearly half of all mobile shoppers are interested in using apps instead of a mobile browser (45 percent of tablet shoppers and 49 percent of smartphone shoppers). The research is based on an online survey with a sample of 1,003 consumers. Identify potential concerns with coverage, nonresponse, sampling, and measurement errors.

A rental car company has noticed that the distribution of the number of miles customers put on rental cars per day is somewhat skewed to the right, with an occasional high outlier. The distribution has a mean of 80 miles and a standard deviation of 50 miles.

Draw a picture of a normal curve with this mean and standard deviation (80 miles and 50 miles), and use the information in the picture to verify that the distribution of number of miles must be skewed to the right and/or have occasional high outliers rather than being normally distributed.

Nationally, about 11% of the total U.S. wheat crop is destroyed each year by hail. An insurance company is studying wheat hail damage claims in Weld County, Colorado. A random sample of 16 claims in Weld County gave the following data (1% wheat crop lost to hail).

$$\begin{array}{rrrrrrrr} 15 & 8 & 9 & 11 & 12 & 20 & 14 & 11 \\ 7 & 10 & 24 & 20 & 13 & 9 & 12 & 5 \end{array}$$

The sample mean is $\bar{x}=12.5 \%$. Let x be a random variable that represents the percentage of wheat crop in Weld County lost to hail. Assume that x has a normal distribution and $\boldsymbol{\sigma}=5.0 \%$. Do these data indicate that the percentage of wheat crops lost to hail in Weld County is different (either way) from the national mean of 11%? Use $\alpha=0.01$. Find (or estimate) the P-value. Sketch the sampling distribution and show the area corresponding to the P-value.

In 1960, census results indicated that the age at which American men first married had a mean of 23.3 years. It is widely suspected that young people today are waiting longer to get married. We want to find out if the mean age of first marriage has increased during the past 40 years. a) Write appropriate hypotheses. b) We plan to test our hypothesis by selecting a random sample of 40 men who married for the first time last year. Do you think the necessary assumptions for inference are satisfied? Explain. c) Describe the approximate sampling distribution model for the mean age in such samples. d) The men in our sample married at an average age of 24.2 years, with a standard deviation of 5.3 years. What 's the P-value for this result? e) Explain (in context) what this P-value means. f) What's your conclusion?

Please provide the following information. What sampling distribution will you use? What assumptions are you making? Compute the value of the sample test static. Do professional golfers play better in their first round? Let row B represent the score in the fourth (and final) round, and let row A represent the score in the first round of a professional golf tournament. A random sample of finalists in the British Open gave the following data for their first and last rounds in the tournament

$$\begin{array}{|l|lllllllll|} \hline B: \text { Last } & 73 & 68 & 73 & 71 & 71 & 72 & 68 & 68 & 74 \\ \hline \text { A: First } & 66 & 70 & 64 & 71 & 65 & 71 & 71 & 71 & 71 \\ \hline \end{array}$$

Do the data indicate that the population mean score on the last round is higher than that on the first? Use a 5% level of significance.

USA Today reported that the state with the longest mean life span in Hawaii, where the population mean life span is 77 years. A random sample of 20 obituary notices in the Honolulu Advertizer gave the following information about life span (in years) of Honolulu residents:

$$\begin{array}{llllllllll} 72 & 68 & 81 & 93 & 56 & 19 & 78 & 94 & 83 & 84 \\ 77 & 69 & 85 & 97 & 75 & 71 & 86 & 47 & 66 & 27 \end{array}$$

i. Use a calculator with mean and standard deviation keys to verify that $\bar{x}=71.4$ years and $s \approx 20.65$ years. ii. Assuming that life span in Honolulu is approximately normally distributed, does this information indicate that the population mean life span for Honolulu residents is less than 77 years? Use a 5% level of significance. Find (or estimate) the P-value. Sketch the sampling distribution and show the area corresponding to the P-value.

A fast-food restaurant uses an automated filling machine to pour its soft drinks. The machine has different settings for small, medium, and large drink cups. When the large setting is chosen, the amount of liquid dispensed by the machine is approximately normally distributed with mean $\mu_{1}=27$ ounces and standard deviation $\sigma_{1}=0.8$ ounce. When the medium setting is chosen, the amount of liquid dispensed is approximately normally distributed with mean $\mu_{2}=17$ ounces and standard deviation $\sigma_{2}=0.5$ ounce. The restaurant manager measures the amount of liquid in each of 20 randomly selected cups filled with the large setting and 25 randomly selected cups filled with the medium setting. Let $\bar{x}_{1}-\bar{x}_{2}$ be the difference in the sample mean amount of liquid under the two settings. What is the shape of the sampling distribution of $\bar{x}_{1}-\bar{x}_{2} ?$ Why?

Determine the type of sampling technique used in each case. Choose from convenience, simple random, systematic, stratified or quota sample.

a. A fishmonger selects six fish whose lengths are between $11 \mathrm{~cm}$ and $15 \mathrm{~cm}$, seven fish whose lengths are between $11 \mathrm{~cm}$ and $15 \mathrm{~cm}$, and three fish whose lengths are between $21 \mathrm{~cm}$ and $25 \mathrm{~cm}$ to test for taste.

b. The school newspaper interviews 50 high school female teachers and 50 high school male teachers.

c. A DJ chooses every fourth song on a playlist.

d. The mathematics club uses a computer to generate 50 random numbers and then picks students whose names correspond to the numbers.

f. A local newspaper selects to interview people at the seaside. It specifies that 90 % of those interviewed must be local residents and 10 % must be tourists.

Match each vocabulary term to its definition.

1. eustress a. The effect of positive events, or the optimal amount of stress that people need to promote health and well-being.
2. catastrophe b. The daily annoyances of everyday life.
3. problem-focused coping c. Actions meant to harm or destroy.
4. escape or withdrawal d. The psychological experience produced by urgent demands or expectations for a person's behavior that come from an outside source.
5. Aggression e. An unpredictable, large-scale event that creates a tremendous need to adapt and adjust as well as overwhelming feelings of threat.
6. displaced aggression f. Taking out one's frustrations on some less threatening or more available target.
7. hassles g. Leaving the presence of a stressor.
8. general adaptation syndrome h. Coping strategies that try to eliminate the source of a stress or reduce its impact through direct actions.
9. emotion-focused coping i. Coping strategies that change the impact of a stressor by changing the emotional reaction to the stressor.
10. pressure j. The three stages of the body's physiological reaction to stress, including alarm, resistance, and exhaustion.

For populations of the marine mussel Mytilus edulis around Long Island, New York, researchers measured the frequency of a particular allele $\left(l a p^{94}\right)$ for an enzyme involved in regulating the mussel's saltwater balance. They presented their data as a series of pie charts linked to sampling sites within Long Island Sound, where the salinity is highly variable, and along the coast of the open ocean, where salinity is constant. Considering the various mechanisms that can alter allele frequency, construct a hypothesis that explains the patterns you observe in the data and that accounts for the following observations: (1) The lap $^{94}$ allele helps mussels maintain osmotic balance in water with a high salt concentration but is costly to use in less salty water; and (2) mussels produce larvae that can disperse long distances before they settle on rocks and grow into adults.

A local news agency conducted a survey about unemployment by randomly dialing phone numbers until it had gathered responses from 1000 adults in the state. In the survey, 19% of those who responded said they were not currently employed. In reality, only 6% of the adults in the state were not currently employed at the time of the survey. Which of the following best explains the difference in the two percentages? (a) The difference is due to sampling variability. We shouldn't expect the results of a random sample to match the truth about the population every time. (b) The difference is due to response bias. Adults who are employed are likely to lie and say that they are unemployed. (c) The difference is due to undercoverage. The survey included only adults and did not include teenagers who are eligible to work. (d) The difference is due to nonresponse. Adults who are employed are less likely to be available for the sample than adults who are unemployed.

Due to quantum fluctuations, laser fields have an inherent uncertainty $\Delta n$ in the number of photons $n$ contained in the field. For an ideal laser field, this inherent uncertainty is given by

$$\Delta n=\sqrt{\bar{n}}$$

where $\bar{n}$ is the mean number of photons in the field. A signal cannot be extracted from noise unless the mean signal photon number $\bar{n}$ exceeds the uncertainty in photon number $\sqrt{\bar{n}}$. This requirement gives

$$\bar{n}>\sqrt{\bar{n}} \text { or } \bar{n}>1$$

Thus the minimum optical signal that can be extracted from the inherent quantum noise in an ideal laser field must contain, on average, at least one photon per detector sampling time. Use this relation to estimate the minimum detectable signal power in an ideal laser field of wavelength $1.5 \mu \mathrm{m}$ using a detector with a detection observation time of $1 \mu \mathrm{s}$.

An online poll at a website asked: A nationwide ban of the diet supplement ephedra went effect recently. The herbal stimulant has been linked to 155 deaths and many more heart attacks and strokes. Ephedra manufacturer NVE Pharmaceuticals, claiming that the FDA lacked proof that ephedra is dangerous if used as directed, was denied a temporary restraining order on the ban yesterday by a federal judge. Do you think that ephedra should continue to be banned nationwide? 65% of 17,303 respondents said "yes." Comment on each of the following statements about this poll: a) With a sample size that large, we can be pretty certain we know the true proportion of Americans who think ephedra should be banned. b) The wording of the question is clearly very biased. c) The sampling frame is all Internet users. d) Results of this voluntary response survey can't be reliably generalized to any population of interest.

At December 31, 2020, Coburn Corp. has assets of $\$ 10,000,000$, liabilities of $\$ 6,000,000$, common stock of $\$ 2,000,000$ (representing $2,000,000$ shares of $\$ 1$ par common stock), and retained earnings of $\$ 2,000,000$. Net sales for the year 2020 were $\$ 18,000,000$, and net income was $\$ 800,000$. As auditors of this company, you are making a review of subsequent events on February 13, 2021, and you find the following.

1. On February 3, 2021, one of Coburn's customers declared bankruptcy. At December 31, 2020, this company owed Coburn $\$ 300,000$, of which $\$ 60,000$ was paid in January 2021.

2. On January 18, 2021, one of the three major plants of the client burned.

3. On January 23, 2021, a strike was called at one of Coburn's largest plants, which halted $30 \%$ of its production. As of today (February 13), the strike has not been settled.

4. A major electronics enterprise has introduced a line of products that would compete directly with Coburn's primary line, now being produced in a specially designed new plant. Because of manufacturing innovations, the competitor has been able to achieve quality similar to that of Coburn's products but at a price $50 \%$ lower. Coburn officials say they will meet the lower prices, which are high enough to cover variable manufacturing and selling costs but which permit recovery of only a portion of fixed costs.

5. Merchandise traded in the open market is recorded in the company's records at $\$ 1.40$ per unit on December 31,2020. This price had prevailed for 2 weeks, after release of an official market report that predicted vastly enlarged supplies; however, no purchases were made at $\$ 1.40$. The price throughout the preceding year had been about $\$ 2$, which was the level experienced over several years. On January 18, 2021, the price returned to $\$ 2$, after public disclosure of an error in the official calculations of the prior December, correction of which destroyed the expectations of excessive supplies. Inventory at December 31, 2020, was on a lower-of-LIFO-cost-or-market basis.

6. On February 1, 2021, the board of directors adopted a resolution accepting the offer of an investment banker to guarantee the marketing of $\$ 1,200,000$ of preferred stock.

State in each case how the 2020 financial statements would be affected, if at all.