1. Consider the following XML file:

<root>

<students>

<element>

<ID>100345</ID>

<Nationality>USA</Nationality>

<Program>ICT</Program>

<age>23</age>

<name>John</name>

</element>

<element>

<ID>100876</ID>

<Nationality>MALAYSIA</Nationality>

<Program>CS</Program>

<age>28</age>

<name>Awang</name>

</element>

<element>

<ID>100257</ID>

<Nationality>AUSTRALIA</Nationality>

<age>25</age>

<name>Alex</name>

</element>

</students>

</root

Write an XQUERY to display the information for all students who are not Malaysians or older than 25.

3. The economic student association at the University X is hiring students to make banners “I love economics” for the coming conference. Complete the following table and plot the production function and the cost function for producing banners. (Marks 10)
Number of
Students
Hired Output Marginal
Product of
Labour Cost of
Equipment Cost of
Students
Hired Total Cost
0 0 100 0
1 100 100 20
2 80 100 140
3 240 100 60
4 40 100 180
5 300 100 100

Using Visual Studio in C#; create a grading application for a class of ten students. The application should request the names of the students in the class. Students take three exams worth 100 points each in the class. The application should receive the grades for each student and calculate the student’s average exam grade. According to the average, the application should display the student’s name and the letter grade for the class using the grading scheme below. Grading Scheme: • A = 90-100 • B = 80-89 • C = 70-79 • D = 60-69 • F = <60

It has been reported that 45% of all college students use Twitter If we survey a simple
random sample of n = 225 college students and ask if they use Twitter, the percentage who
say “yes” will vary if the sampling method is repeated. In fact, the sampling distribution of
the percentage who say they use Twitter, in many samples of size n = 225, will be Normal in
shape, with mean (or center) of 45% and standard deviation of 3.3%. Based on this
information, we know that the probability of obtaining a sample (of size n = 225) where
39% or fewer students say they use Twitter is

27.) Use the following information to answer questions 27 & 28:

A statistics teacher wants to see if there is any difference in the performance of students on the final exam if she gives them orange jelly beans before the exam. She has a theory that orange jelly beans will change the results, but she isn't sure in which direction. She knows that the population mean score on the exam when students do not have orange jelly beans is 82 and that exam scores have an approximately symmetric distribution. She gives orange jelly beans to 25 randomly selected students and finds that these students had a sample mean score of 87 with a sample standard deviation of 10. She wants to have 95% confidence in her result.

27.) Conduct a hypothesis test using the p-value approach.

28.) Conduct a hypothesis test using the confidence interval approach.

In a study entitled How Undergraduate Students Use Credit Cards, Sallie Mae reported that undergraduate students have a mean credit card balance of $3173. This figure was an all-time high and had increased drastically over the previous five years. Assume that a current study is being conducted to determine whether it can be concluded that the mean credit card balance for undergraduate students has continued to increase compared to the April 2009 report (i.e. greater than 3173). Based on previous studies, use a population standard deviation, σ = $1000. A random sample of 180 undergraduate students was taken and the sample mean credit card balance was $3,325. Let α = 0.01.

1. state the null & alternative hypothesis

2. construct the rejection region

3. calculate test statistic (z)

4. state decision to reject or not to reject

Assume that we ran an experiment on providing free access to netflix to college students and we wanted to know how it will impact their exam scores. We gave 400 student free access to Netflix and 400 students did not get it for free.

a. If the average exam score for treatment students is 85 and the average exam score for control students is 80, while the standard deviation for each group is 60, what would the 95% confidence intervals be for the average of each group? (To be accurate please use 1.96 SE’s to compute the intervals).

b. Is there a statistically significant difference between the two groups? Why?

c. Imagine instead that the standard deviation for each group was 40. What would be the lowest grade possible (whole number) that the treatment group could get where we would still be able to detect a statistically significant difference?

A researcher wants to know how optimistic students are about getting a job after they finish their university studies. The researcher randomly selected 10 students from the graduating class to complete a short questionnaire. A key question asked what was the likelihood that the student would get their preferred job soon after graduation. The questionnaire used a 7-point scale from extremely unlikely (1) to extremely likely (7). The researcher wanted to know if students’ responses were consistently above or below the neutral point on the scale (hint: μ = 4). The students’ ratings are below.

Approximately, what is the observed value of the test statistic and what is your decision regarding the null hypothesis?

You are conducting a study to determine the impact of a new reading intervention on students test scores. You randomly assign 40 students to either the intervention group or the control group (those not participating in the intervention). You also break the students into morning and afternoon classes to determine which is the best time of day to conduct the intervention.

1. What is the dependant variable?

2. What is/are the independent variable(s)?

3. How many cells will there be?

4. If we divide the groups evenly how many students will appear in each cell?

5. What type of design is this? (Again, Be Specific!)

6. Assume that you conduct an ANOVA with 3 groups and 60 subjects (evenly divided between the 3 groups) and receive an F-value of 3.30. How would you write this result in a study? (Be sure to include whether or not it is a significant result)