Hypothesis Test Analysis
Shawnda Peluaga
Research and Evaluation
October 30, 2006

Business Problem
You are the manager of a large firm. Lately complaints have surfaced that an increased number of incoming calls are being dropped or misrouted. Yesterday, as you walked by one older employee, you noticed that he was fiddling with his hearing aid and not paying attention to the phone. A call came in and only because you were there and intervened was the call answered. This particular phone operator had been reprimanded three months earlier for tardiness. Your instinct is to fire this phone rep or encourage him to retire (he is old enough). You also know that this gentleman is well liked within the company. Pose several hypotheses that might account for the dropped or misrouted calls. How would you test these hypotheses? Analysis

#1. "Short Timers Disease" This is the disease also known as the "Couldn't care less syndrome. Perhaps the man knows that he wants to retire or is getting ready to announce it. He could be thinking on terms of time left and doesn't really care what happens, so he is careless and distracted. He may be seeing how far he can push the limits and force the business into a decision that may be incorrect. I would talk with the man and see where his future goals lie. If he were sincere then I would perhaps give him another chance with a warning that if this type of behavior continues, I would be inclined to take disciplinary actions relating to his job. This may inspire a "Short Timer" to go ahead and take the early leap. #2 Hearing Loss I think that this may be more obvious. Tinkering with his hearing aid may be a sign that something is wrong that he doesn't know how to fix or that he can't fix due to other reasons. I would seek the reason for the earlier tardiness and more than likely see that it may relate to oversleeping an alarm or such. In this situation I would see if we could make some suggestions as to the condition of...

...HYPOTHESISTESTING
WHAT IS THIS HYPOTHESIS????
• In simple words it means a mere assumption or supposition to be proved of disproved.
• But, for a researcher it is a formal question that he intends to resolve.
• Example: I assume that 1) under stress and anxiety a person goes into depression.
2) It leads to aggressive behaviour.
Eg. : Students who get better counselling in a university will show a greater increase in creativity than students who were not counselled.
• So, the hypothesis should be capable of being verified and tested.
CHARACTERISTICS
• Should be clear and precise – inferences not reliable
• Capable of being tested
“ A hypothesis is testable if other deductions can be made from it which, in turn can be confirmed or disproved by observation.”
• Should be limited in scope and must be specific
• Should be stated in simple terms -understandable by all concerned.
• Must explain the facts that gave rise to the need for explanation.
BASIC CONCEPTS: NULL & ALTERNATIVE HYPOTHESIS
• If we are to compare two methods A & B and both are equally good, then this assumption is termed as null hypothesis(H0)
• If it is stated that method A is better than method B-alternative hypothesis(Ha)
LEVEL OF SIGNIFICANCE
• A very important concept in the context of hypothesistesting
• It is represented in a % age...

...HypothesisTesting For a Population Mean
The Idea of HypothesisTesting
Suppose we want to show that only children have an average higher cholesterol level than the national average. It is known that the mean cholesterol level for all Americans is 190. Construct the relevant hypothesis test:
H0: = 190
H1: > 190
We test 100 only children and find that
x = 198
and suppose we know the population standard deviation
= 15.
Do we have evidence to suggest that only children have an average higher cholesterol level than the national average? We have
z is called the test statistic.
Since z is so high, the probability that Ho is true is so small that we decide to reject H0 and accept H1. Therefore, we can conclude that only children have a higher average cholesterol level than the national average.
Rejection Regions
Suppose that = .05. We can draw the appropriate picture and find the z score for -.025 and .025. We call the outside regions the rejection regions.
We call the blue areas the rejection region since if the value of z falls in these regions, we can say that the null hypothesis is very unlikely so we can reject the null hypothesis
Example
50 smokers were questioned about the number of hours they sleep each day. We want to test the hypothesis that the smokers need less...

...all, the video did a fair job buttressing my understanding of hypothesistesting. The textbook explained the aspects and steps of hypothesistesting in a legible fashion, while the video helped demonstrate a real-life application.
I learned from the text that hypothesistesting is a “Procedure for deciding whether the outcome of a study (results from a sample) supports a particular theory or practical innovation (which is thought to apply to a population)” (Aron A., Aron, E., and Coups, 2011, p. 145). I also learned that hypothesistesting follows a set procedure that appears as follows:
Step 1) Restate the question as a research hypothesis and a null hypothesis about the populations
- Basically, a researcher constructs a hypothesis. Then he/she forms a null hypothesis that opposes the research hypothesis in
polar fashion. To help support one’s research hypothesis, one has to disprove the null hypothesis.
Step 2) Determine the characteristics of the comparison distribution
- When using two or more samples, one must gather information about the distribution of means.
Step 3) Determine the cutoff sample score on the comparison distribution at which the null hypothesis should be rejected
- Most researchers...

...Nonparametric HypothesisTesting Paper
ABC’s real estate agency has recently expanded its business and is in the process of conducting research on housing prices within 10 miles of its new office. Team B has been given the task by ABC real estate to conduct the needed research. The team will be able to answer at the end of the research if the prices in Santa Cruz, California, are less than the prices of house in Scott’s Valley, California. Throughout this research process the team will formulate the hypothesis statement, perform a five-step hypothesis test, discuss which nonparametric test was needed, and discuss the results from this data research compare to past research completed.
Five-Step Hypothesis Test
The five-step hypothesis test will determine if consumers have a greater satisfaction when the consumer(s) pay more for the home.
Step one is to state the null hypothesis and alternative hypothesis:
Ho: µ1 = µ2 No difference in satisfaction
Ho: µ1≠ µ2 Satisfaction differs for the two groups
Step two evaluates if the assumptions have been met through the Mann-Whitney test selection that will compare the two populations and will assume equal variances with a 95% confidence level, the significance level is .05. The decision rule is to reject Ho if z>1.645.
Step three the ranks are summed and calculated using the Wilcoxon – Mann-Whitney test....

...Precipitation HypothesisTesting Paper
Learning Team One
Research and Evaluation II – RES 342
University of Phoenix
Precipitation HypothesisTesting
Learning team one will test if there is more precipitation in the three months of the spring in 2006 or is it greater than or equal to the three months in the winter in Rockville, which is located in Montgomery County, Maryland. We will look at the validity of the local average precipitation (rainfall) during the months of December through March and March through June by using the five (5) Step Hypothesistesting technique.
The testing will begin with our null and alternate hypothesis statements. Second, we will determine the level of significance or probability of rejecting the null hypothesis when it is true (Lind, Marchal, Wathwn, 2004). Third, we will select a test statistic or value from the sample. Fourth, we will formulate the decision rule, which will determine whether we accept or reject the null hypothesis. Finally, we will compare our test statistic to our critical value and decide to accept or reject the hypothesis. Our sample data will consist of spring months March 21 through June 20 and winter months December 21 through March 20.
Our learning team compared the average precipitation for the winter...

...Statistics for Business Intelligence – HypothesisTesting
Index:
1. What is Hypothesistesting in Business Intelligence terms?
2. Define - “Statistical HypothesisTesting” – “Inferences in Business” – and “Predictive Analysis”
3. Importance of HypothesisTesting in Business with Examples
4. Statistical Methods to perform HypothesisTesting in Business Intelligence
5. Identify Statistical variables required to compute Hypothesistesting.
a. Correlate computing those variables from the data available in normalized tables arranged in row x columns.
6. Computing Statistical HypothesisTesting for Business Decisions using Algorithms
7. User Interface Development for Presentation of Hypothesis feature
8. How does it fit in Prajna?
1. What is Hypothesistesting in Business Intelligence?
HypothesisTesting – is used to prove or disprove the research (Business proposed decision) hypothesis by providing more measurable or concrete hypothesis statement. for example, a research hypothesis could be that the stock market index reflects the state of monsoon in the country. A statistical hypothesis might...

...Address using an independent or related samples t test.
2. Identify the independent (grouping) and dependant (response) variables important to study
3. Explain whether an independent sample or related sample t test is appropriate and why
4. Generate a hypothesis, including null and alternative hypothesis
5. Describe what information the effect size will tell you and what information the effect size will tell you and what information the p value or critical value approach will not
6. Using realistic numbers for the degrees of freedom, sample size and t statistic, report hypothetical results in 2-3 sentences
Solution: (1) Let’s consider the following research situation: The incidence of Congestive heart failure (CHF) is going to be studied based on two different diet groups: one group receives a special diet (a diet designed for preventing CHF), and a control group (which doesn’t receive any diet). We are interested in assessing whether there is a difference in the incidence of CHF for these two groups. In order to perform the analysis, a two-independent t-test will be used.
(2) In this case, the independent (grouping) variable is DIET, and the dependent (response) variable is CHF incidence rate.
(3) This analysis corresponds to an independent-samples design, because the treatments (diet/no diet) are applied to different subjects.
(4) We are interested in the following research question:
Is there a...

...Sample HypothesisTesting
I am working on a problem in Excel but I am having trouble with my T- Distribution. I am using the TDIST function but have been unsucessful in my calculations.
Here is the case scenario:
One hundred customers at the Mall of Elbonia (MoE) were given a brief interview as they concluded their shopping trips. Examine the resulting data in the Mall of Elbonia Interview Results file. For each customer (by row), the spreadsheet contains data on:
The customer's gender.
How long the customer spent in the mall.
How much he or she spent on food and clothing purchases.
The customer's rating of the mall's friendliness and attractiveness.
A.) MoE's concessions manager believes the average amount that mall customers spend on food during a visit has increased over the historical average of $18.75, due to the opening of some new upscale restaurants in the mall. Use the data in the file to test his hypothesis.
Answers
• What is the null hypothesis?
The null hypothesis tested is
H0: The average amount that mall customers spend on food during a visit ≤ $18.75 (µ ≤ 18.75)
• Would you reject it at alpha = .05?
The alternative hypothesis is
H1: The average amount that mall customers spend on food during a visit > $18.75 (µ > 18.75)
Significance level = 0.05
Test Statistic used is , where = 19.932478964, n = 100, s = 4.254541656 (Please see the excel...