The mean cost of domestic airfares in the United States rose to an all-time high of $380 per ticket. Airfares were based on the total ticket value, which consisted of the price charged by the airlines plus any additional taxes and fees. Assume domestic airfares are normally distributed with a standard deviation of $115.

a. What is the probability that a domestic airfare is $555 or more (to 4 decimals)?

b. What is the probability that a domestic airfare is $250 or less (to 4 decimals)?

c. What if the probability that a domestic airfare is between $320 and $490 (to 4 decimals)?

d. What is the cost for the 5% highest domestic airfares? (rounded to nearest dollar)

In the United States, voters who are neither Democrat nor Republican are called Independent. It is believed that 13% of voters are Independent. A survey asked 33 people to identify themselves as Democrat, Republican, or Independent.

A. What is the probability that none of the people are Independent?

Probability =

B. What is the probability that fewer than 6 are Independent?

Probability =

C. What is the probability that more than 3 people are Independent?

Probability =

Assume that annual interest rates are 8 percent in the United States and 7 percent in Turkey. An FI can borrow (by issuing CDs) or lend (by purchasing CDs) at these rates. The spot rate is $0.6571/Turkish lira (TL).

a. If the forward rate is $0.6735/TL, how could the bank arbitrage using a sum of $8 million? What is the spread earned? (Do not round intermediate calculations. Round your answer to 4 decimal places. (e.g., 32.1616))
b. At what forward rate is this arbitrage eliminated? (Do not round intermediate calculations. Round your answer to 5 decimal places. (e.g., 32.16161))

Describe one other epidemiological threat in the United States that has been in the news in the past 2 years that is not influenza. Discuss how this threat affected the community, including local, state, and federal resources that were brought in to restore normal business and life. Include any media examples that discussed either good or poor reactions by stakeholders and approximately how long the area was directly impacted compared to the previous historical timelines for this type of threat?

Fresh!Now! is a chain of grocery stores in the United States with 1921 grocery stores in total, some of which also sell bakery goods and freshly made food-to-go. Fresh!Now!’s goal is to provide good quality fresh vegetables at affordable prices. However, given the existing market of organic food supplies, Fresh!Now! is facing tremendous competition. They realize that Fresh!Now! has to make their stores more attractive to customers.

In 19 stores across Massachusetts and New York, they have implemented a new concept to present the vegetables in the stores and have collected information of the average daily profit of leafy vegetables (in dollar) per customer per store (see table below). Janine, the head of the analytics department at Fresh!Now!, has tasked you with developing an anlaysis to better understand if the new concept has any effect.

1. Your first task it to create a 95% confidence interval for the mean of the dataset using the sample collected from Massachusetts and New York.

What is the upper limit of this confidence interval?

Round your answer to three decimals places (e.g. if your calculation results in 12.9237 put in 12.924).

2. What is the lower limit of this confidence interval?

Round your answer to three decimals places (e.g. if your calculation results in 12.9237 put in 12.924)

3. To understand if the new concept has taken effect, you want to conduct a hypothesis test. Average daily profit per customer per store for the leafy vegetables in all other Fresh!Now! grocery stores is 14.2.

You formulate the following hypothesis test:

H0: Average daily profit at Fresh!Now! in the New York/Massachusetts stores is not higher than the average daily profit of all other Fresh!Now! grocery stores at a confidence level of 95%.

H1: Average daily profit at Fresh!Now! in the New York/Massachusetts stores is higher than the average daily profit of all other Fresh!Now! grocery stores at a confidence level of 95%.

Calculate the test-statistic for the hypothesis test above.

Round your answer to three decimal places (e.g. if your calculation results in 12.9237 put in 12.924).

A

2010

poll asked people in the United States whether they were satisfied with their financial situation. A total of

338

out of

833

people said they were satisfied. The same question was asked in

2012

, and

304

out of

1156

people said they were satisfied.

Part 1 of 2

Your Answer is correct

(a) Construct a

99.8%

confidence interval for the difference between the proportions of adults who said they were satisfied in

2012

and

2010

. Let

p1

denote the proportion of adults who said they were satisfied in

2010

.Use tables to find the critical value and round the answer to at least three decimal places.

A

99.8%

confidence interval for the difference between the proportions of adults who said they were satisfied in

2012

and

2010

is  

<0.077<−p1p20.209.

Part: 1 / 2

1 of 2 Parts Complete

Part 2 of 2

(b) A sociologist claims that the proportion of people who are satisfied increased from  

2010

to  

2012

by more than

0.22

. Does the confidence interval contradict this claim?

Snow avalanches can be a real problem for travelers in the western United States and Canada. A very common type of avalanche is called the slab avalanche. These have been studied extensively by David McClung, a professor of civil engineering at the University of British Columbia. Suppose slab avalanches studied in a region of Canada had an average thickness of μ = 67 cm. The ski patrol at Vail, Colorado, is studying slab avalanches in its region. A random sample of avalanches in spring gave the following thicknesses (in cm).

59 51 76 38 65 54 49 62 68 55 64 67 63 74 65 79

(i) Use a calculator with sample mean and standard deviation keys to find x and s. (Round your answers to two decimal places.) x = cm s = cm

(ii) Assume the slab thickness has an approximately normal distribution. Use a 5% level of significance to test the claim that the mean slab thickness in the Vail region is different from that in the region of Canada.

(a) What is the level of significance?

Snow avalanches can be a real problem for travelers in the western United States and Canada. A very common type of avalanche is called the slab avalanche. These have been studied extensively by David McClung, a professor of civil engineering at the University of British Columbia. Suppose slab avalanches studied in a region of Canada had an average thickness of μ = 68 cm. The ski patrol at Vail, Colorado, is studying slab avalanches in its region. A random sample of avalanches in spring gave the following thicknesses (in cm).

(i) Use a calculator with sample mean and standard deviation keys to find x and s. (Round your answers to two decimal places.)

(ii) Assume the slab thickness has an approximately normal distribution. Use a 1% level of significance to test the claim that the mean slab thickness in the Vail region is different from that in the region of Canada.

(a) What is the level of significance?


State the null and alternate hypotheses.

H₀: μ = 68; H₁: μ > 68 H₀: μ ≠ 68; H₁: μ = 68     H₀: μ = 68; H₁: μ < 68 H₀: μ < 68; H₁: μ = 68 H₀: μ = 68; H₁: μ ≠ 68

(b) What sampling distribution will you use? Explain the rationale for your choice of sampling distribution.

The Student's t, since we assume that x has a normal distribution and σ is unknown. The Student's t, since we assume that x has a normal distribution and σ is known.     The standard normal, since we assume that x has a normal distribution and σ is known. The standard normal, since we assume that x has a normal distribution and σ is unknown.

What is the value of the sample test statistic? (Round your answer to three decimal places.)


(c) Estimate the P-value.

P-value > 0.250 0.100 < P-value < 0.250     0.050 < P-value < 0.100 0.010 < P-value < 0.050 P-value < 0.010