A set of solar batteries is used in a research satellite. The satellite can run on only one battery, but it runs best if more than one battery is used. The variance σ² of lifetimes of these batteries affects the useful lifetime of the satellite before it goes dead. If the variance is too small, all the batteries will tend to die at once. Why? If the variance is too large, the batteries are simply not dependable. Why? Engineers have determined that a variance of σ² = 23 months (squared) is most desirable for these batteries. A random sample of 26 batteries gave a sample variance of 15.2 months (squared). Using a 0.05 level of significance, test the claim that σ² = 23 against the claim that σ² is different from 23.

(a) What is the level of significance?


State the null and alternate hypotheses.

H_o: σ² = 23; H₁: σ² > 23H_o: σ² = 23; H₁: σ² ≠ 23    H_o: σ² > 23; H₁: σ² = 23H_o: σ² = 23; H₁: σ² < 23

(b) Find the value of the chi-square statistic for the sample. (Round your answer to two decimal places.)


What are the degrees of freedom?


What assumptions are you making about the original distribution?

We assume a exponential population distribution.We assume a binomial population distribution.    We assume a normal population distribution.We assume a uniform population distribution.

(c) Find or estimate the P-value of the sample test statistic.

P-value > 0.1000.050 < P-value < 0.100    0.025 < P-value < 0.0500.010 < P-value < 0.0250.005 < P-value < 0.010P-value < 0.005

(d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis?

Since the P-value > α, we fail to reject the null hypothesis.Since the P-value > α, we reject the null hypothesis.    Since the P-value ≤ α, we reject the null hypothesis.Since the P-value ≤ α, we fail to reject the null hypothesis.

(e) Interpret your conclusion in the context of the application.

At the 5% level of significance, there is insufficient evidence to conclude that the variance of battery life is different from 23.At the 5% level of significance, there is sufficient evidence to conclude that the variance of battery life is different from 23.    

(f) Find a 90% confidence interval for the population variance. (Round your answers to two decimal places.)

(g) Find a 90% confidence interval for the population standard deviation. (Round your answers to two decimal places.)

A set of solar batteries is used in a research satellite. The satellite can run on only one battery, but it runs best if more than one battery is used. The variance σ² of lifetimes of these batteries affects the useful lifetime of the satellite before it goes dead. If the variance is too small, all the batteries will tend to die at once. Why? If the variance is too large, the batteries are simply not dependable. Why? Engineers have determined that a variance of σ² = 23 months (squared) is most desirable for these batteries. A random sample of 30 batteries gave a sample variance of 14.4 months (squared). Using a 0.05 level of significance, test the claim that σ² = 23 against the claim that σ² is different from 23.

(a) What is the level of significance?


State the null and alternate hypotheses.

H_o: σ² = 23; H₁: σ² > 23H_o: σ² = 23; H₁: σ² < 23    H_o: σ² > 23; H₁: σ² = 23H_o: σ² = 23; H₁: σ² ≠ 23

(b) Find the value of the chi-square statistic for the sample. (Round your answer to two decimal places.)


What are the degrees of freedom?


What assumptions are you making about the original distribution?

We assume a normal population distribution.We assume a uniform population distribution.    We assume a exponential population distribution.We assume a binomial population distribution.

(c) Find or estimate the P-value of the sample test statistic.

P-value > 0.1000.050 < P-value < 0.100    0.025 < P-value < 0.0500.010 < P-value < 0.0250.005 < P-value < 0.010P-value < 0.005

(d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis?

Since the P-value > α, we fail to reject the null hypothesis.Since the P-value > α, we reject the null hypothesis.    Since the P-value ≤ α, we reject the null hypothesis.Since the P-value ≤ α, we fail to reject the null hypothesis.

(e) Interpret your conclusion in the context of the application.

At the 5% level of significance, there is insufficient evidence to conclude that the variance of battery life is different from 23.At the 5% level of significance, there is sufficient evidence to conclude that the variance of battery life is different from 23.    

(f) Find a 90% confidence interval for the population variance. (Round your answers to two decimal places.)

(g) Find a 90% confidence interval for the population standard deviation. (Round your answers to two decimal places.)

Americans should learn to live without these two imported products. But, they should not have to give up these two imported products. Justify your reasons for each statement.(8-10 sentences)

This is a sample response to help clarify the question:

The first important import that the US should be able to live without is crude oil. The US produces a large percentage of the oil it needs and only needs roughly 25% more to meet its demand. If the US can cut its usage by that last 25% or so, we would be able to be self-sufficient and not have to rely on other countries for this import. Thirty seven percent of the energy the US consumes is from petroleum, increasing the usages of natural gas and renewable sources, not only will the US benefit but also the environment will as well.

The US should be able to live without importing automobiles. I say this because motor vehicles is one of the top imports of the US at the same time as being the number three ranked export. I like the ability for a consumer to buy what they like with the amounts of cars to choose from. However, there are so many domestic cars, ranging from economy cars to large luxury vehicles. If these are such a good export, we should be able to live with not bringing in cars from other countries and look to drive American made cars.

The two products that I think Americans should not have to live without are somewhat similar. Both are beverages, but enjoyed differently. The first is real good Columbian grown coffee, sometimes it is the best part of getting out of bed in the morning! The US imports about $6.3 billion in coffee each year, which is the highest at 19%. As we tend to be labeled as work-aholics, coffee is a big player is keeping us on the go. The second import I think Americans should not have to give up is the import of beer. Beer is made with such cultural influences, and some of the best beers around are imported. I have been to Germany twice, and I will say, their beer is unmatchable. Even with the increase in craft brewing in the US, ending the importing Canadian beers, European beers and Mexican beers is just something I do not want to ever see.

Briefly explain what each of these acronyms mean and describe the type of services each provide.

ACO:

HMO:   

PPO:   

EPO:

Calculate the elasticity of demand using the data shown in the table below.  Use the midpoint method, and show all your work.

The Eric Challenge: Assume you have issues with your back after taking too many health economics exams. Also that you have a budget of $5,400 and you have a choice of selecting two good therapies, hot massage, at $50 per hr., and electro acupuncture, at $60 per hr. Estimate your budget constraint line and calculate your intercepts.

Consider the graph below and explain the meaning of it.

The Sara Challenge: Below is a list of my former students and their monthly compensation. As good economist, define the below of income distribution for this group. Please note, similarity of names with our current class is a simple coincidence!

IN THIS EXERCISE, YOU WILL SEE A CORRELATION MATRIX. EXAMINE THE MATRIX AND ANSWER THE QUESTIONS THAT FOLLOW.

1. Which two variables have the strongest (largest) relationship?

2. Which two variables have the weakest (smallest) relationship?

3. Which two variables have the strongest positive relationship?

4. which two variables have the stronger negative relationship?

5. Which two variables have the weakest positive relationship?
6. Which two variables have the weakest negative relationship?

7. Which variables go down when V$ goes up?

8. Which variable is most likely to increase as V3 increases?

5-Describe two of the following terms/concepts. (FOCUS ON ORIGINALITY) Seasonal unemployment Underemployment Unemployment benefits 6-Describe two of the following terms/concepts. (FOCUS ON ORIGINALITY) Inflation Hyperinflation Deflation 7-Describe two of the following terms/concepts. (FOCUS ON ORIGINALITY) Contractionary fiscal policy Discretionary fiscal policy Expansionary fiscal policy 8-Describe two of the following terms/concepts. (FOCUS ON ORIGINALITY) Federal Reserve System Money market mutual fund Reserves 9-Describe two of the following terms/concepts. (FOCUS ON ORIGINALITY) Balance sheet Federal funds rate Required reserves 10-Describe two of the following terms/concepts. (FOCUS ON ORIGINALITY) International Monetary Fund (IMF) Exchange rate Currency devaluation

2. [9 pts] Write the code necessary to properly allocate memory (on the heap) in the following scenarios

a). An array a of n characters
b) An array b of m+n integers
c) An x × y × z matrix m1 of integers initialized to 0s

Use C code

Software Engineering Process Models
Question 4
(a) Give a description of the waterfall process model. In your answer you should describe the main tasks that are conducted, and the order in which they are carried out. You may want to include a diagram to clarify your answer.
[7 marks]
(b) Describe one advantage and one disadvantage of adopting the waterfall process model in comparison to other process models.
[4 marks]
(c) Describe the key principles which underlie Agile software development.
[8 marks]
(d) Risk management is an important part of software project planning. Describe what is meant by a risk and give two examples of risks which could seriously affect a project.
[4 marks]

Write program#2 upload .java file.

2A) Write a java program that uses the Random class to generate a number in the range 21 to 64.  Print the generated number.

2B) Using the Random class and nextInt(6), rolls two die generating two random numbers each in the range 1 through 6. Total by adding the two values together. Print the value of each die, and the total value.

2C) Using the Math class and sqrt(num), calculate the square root of integer twenty-two divided by integer seven, print the result formated to ten decimal places. Hint: the result of the division needs data conversion to support a double.