Sample size
The process of determining the proper sample size was established through a series of calculations and after obtaining all the possible sample sizes, the largest one was taken into consideration to collect the closest number to a representative sample of the population. The following two equations where used: Equation 1:

N=z2 *(p.q)
E2
N= sample size
Z=level of confidence interval at 95% so z=1.96
P=estimated percent of population
E=acceptable sample error expressed as a percent (5%).

Equation 2:

N=s2*z2
E2
N= sample size
S=(minimum-maximum value) and divide the range by 6.
Z=level of confidence interval at 95% so z=1.96.
E=acceptable sample error expressed as a percent (5%).

For each question the series of calculations lead to the following results: The sample size for question 1 is calculated using equation 1 and n=245.8624 rounded to n=246. The sample size for question 2 is calculated using equation 1 and n=368.79 rounded to n=369. The sample size for question 3 is calculated using equation 1 and n=288.12 rounded to n=289. The sample size for question 4 is calculated using equation 1 and n=349.5856 rounded to n=350. The sample size for question 5 is calculated using equation 1 and n=276.5952 rounded to n=277. The sample size for question 6 is calculated using equation 1 and n=248.8624 rounded to n=246. The sample size for question 7 is calculated using equation 1 and n=368.7936 rounded to n=369. The sample size for question 8 is calculated using equation 1 and n=349.5856 rounded to n=350. The sample size for question 9 is calculated using equation 1 and n=368.7936 rounded to n=369. The sample size for question 10, 11, and 12 are calculated using equation 2 the following way: N=4/62*1.962

0.52
N=sample size
S=(5-1)/6=4/6=
Z=95% equivalent to z=1.96
E=the average between two scales. Then 2-1=1/2=0.5
Therefor the sample size n=6.8295 rounded to n=7
The sample size for question 13 is calculated using equation 2...

...3) n = 186, x = 103
A) 0.0643 B) 0.125 C) 0.00260 D) 0.0714
Find the minimum samplesize you should use to assure that your estimate of will be within the required margin of error around the population p.
4) Margin of error: 0.002; confidence level: 93%; and unknown
A) 204,757 B) 410 C) 204,750 D) 405
5) Margin of error: 0.07; confidence level: 95%; from a prior study, is estimated by the
decimal equivalent of 92%.
A) 58 B) 174 C) 51 D) 4
Use the given degree of confidence and sample data to construct a confidence interval for the
population proportion p.
6) When 343 college students are randomly selected and surveyed, it is found that 110 own
a car. Find a 99% confidence interval for the true proportion of all college students who own a car.
A) 0.256 < p < 0.386 B) 0.279 < p < 0.362 C) 0.271 < p < 0.370 D) 0.262 < p < 0.379
Determine whether the given conditions justify using the margin of error E = when
finding a confidence interval estimate of the population mean .
7) The samplesize is n = 9, is not known, and the original population is normally distributed.
A) Yes B) No
Use the confidence level and sample data to find the margin of error E.
8) Systolic blood pressures for women aged 18-24: 94% confidence; n = 92,
x = 114.9 mm Hg, = 13.2 mm Hg
A) 47.6 mm Hg B) 2.3 mm Hg C) 2.6 mm Hg D) 9.6 mm Hg
Use the confidence level and...

...involves obtaining information, not from a sample, but rather from the entire population or universe.
A sample (as opposed sampling) is a subset of the population/universe.
For Marketing Research purposes, sampling usually involves people, not data or things.
Sampling Plans are strategies and mechanics for selecting members of the sample from the population:
1. Define the population. It is usually limited based on some set of characteristics, e.g., males, aged 21-39, who have consumed alcoholic beverages within the past 3 months for a beer study.
2. Choose data collection methodology. What kind of information do you require from the sample, how will they be identified, where are they available, etc.
3. Set sampling frame. This is as exhaustive a list as operationally and economically possible that represents the population and is also accessible utilizing the selected methodology.
4. Choose sampling method.
• Probability samples are those that allow all members of the sampling frame an equal opportunity of selection. Probability samples include Simple Random, Systematic, Stratified and Cluster sampling
• Nonprobability samples do not allow all members of the sampling frame an equal opportunity of selection. Nonprobability samples include Convenience, Judgment, Quota and Snowball sampling.
5. Determine...

...Calculating SampleSize
Types of Samples
Subjective or Convenience Sample
- Has some possibility of bias
- Cannot usually say it is representative
- Selection made by ease of collection
Simple Random Sample
- No subjective bias
- Equal chance of selection; e.g., select the fifth chart seen on every third day
- Can usually be backed to say it is representative
Systematic Sample
- Is a random sample
- Equal chance of selection due to methodology; e.g., computer-generated list of
random numbers, or every fifth name on a generated list
- Can usually be backed to say it is representative
Stratified Sample
- Breakdown the population into subgroups, then take a random sample from each subset
- Can usually be backed to say it is representative
SampleSize Calculation
The Automated Method
If you know your population size and desired confidence level you may use this Web-based calculator to automatically calculate samplesize.
The Manual Calculation Method
To perform samplesize calculation manually, you need the following values:
Population Value: Size of the population from which the sample will be selected. (Number of users or number of encounters)
Expected Frequency of the Factor under Study...

...Samplesizes and confidence
intervals for proportions
Chong Chun Wie
Ext: 2768
ChongChunWie@imu.edu.my
Content
• Sampling distribution of sample means (SDSM)
• Normality Test
• Estimating a population mean: σ known
• Estimating a population mean: σ unknown
• Standard deviation of proportion
• Confidence interval of proportion
• Hypothesis testing with proportion
Population and SampleSamples
Populations
Sampling distribution of
sample means (SDSM)
Sampling distribution
• Example
– Select randomly from the following number (1, 1, 2, 5, 5,
6, 7, 10)
– Mean = 4.625
•
If we choose 3 points randomly and produced the mean
1, 1, 2 = 4, mean = 1.33
2, 5, 6 = 13, mean = 4.33
1, 5, 7 = 13, mean = 4.33
2, 6, 7 = 15, mean = 5
5, 1, 10 = 16, mean = 5.33
Sampling distributions for (a) normal, (b) reverse-Jshaped, and (c) uniform variables
Test for normality
• Shapiro-Wilk Test (SPSS)
• Probability Plot (Minitab)
Estimating a population
mean: σ known
Confidence Interval for µ using
normal distribution
95% confidence interval
• Suppose we want to construct a 95%
confidence interval for μ,
Another word: 95% of all sample means are in the interval
Margin of Error
Z table
95%
confidence
α = 0.05
99%
confidence
α = 0.01
Example 1
• A doctor graduated from IMU is setting up a new
clinic in KL. Before operation, he wants to know
the average charge for common...

...TABLE OF CONTENTS
1.0 INTRODUCTION
Among the factors of production, the human resource element of any organization is most strategic and paramount. Performance appraisal therefore, is an important means by which organizations improve their chances of attaining their key operational goals. Employees, who know what and how much is expected of them, are likely to be more effective than those who are unclear about their role. It is in the light of this that organizations these days are becoming more concerned about effective performance appraisal.
Performance appraisal even though, dates back to the Second World War, the challenges of appraisal system are numerous and varied. This research is focused on the challenges associated with the implementation of performance appraisal system at the Ghana National Scheme (GNSS), to recommend solutions to the challenges where appropriate.
The main objectives of the study are to evaluate the current performance appraisal system at the Ghana National Scheme (GNSS). The study has become necessary due to the challenges facing the GNSS with regards to the implementation of performance appraisal system.
The study was conducted entirely through the use of questionnaire, interviews and discussions. The questionnaire and interviews gathered information on staff views on how the current appraisal system at the GNSS is being implemented. Discussions were focused on some issues relating to the study for meaningful analysis....

...
References : Zikmund, Babin, Carr, and Griffin. (2009). Business Research Methods. 8th edition. Thomson South-Western. ISBN : 978-0324320626.
Chapter 16, Page 410
3. Describe the difference between a probability sample and a nonprobability sample.
The difference between nonprobability and probability sampling is that nonprobability sampling does not involve random selection and probability sampling does. Does that mean that nonprobabilitysamples aren't representative of the population? Not necessarily. But it does mean that nonprobability samples cannot depend upon the rationale of probability theory. At least with a probabilistic sample, we know the odds or probability that we have represented the population well. We are able to estimate confidence intervals for the statistic. With nonprobability samples, we may or may not represent the population well, and it will often be hard for us to know how well we've done so. In general, researchers prefer probabilistic or random sampling methods over nonprobabilistic ones, and consider them to be more accurate and rigorous. However, in applied social research there may be circumstances where it is not feasible, practical or theoretically sensible to do random sampling. Here, we consider a wide range of nonprobabilistic alternatives.
4. In what types of situations is conducting a census more appropriate than...

...Marketing Research
Marketing research is the systematic design, collection, analysis and reporting of data and findings relevant to a specific marketing situation facing the company.” [Philip Kotler]
“the systematic gathering, recording and analyzing of all data about problems relating to the marketing of goods and services.” [The American Marketing Association]
Basic purpose of marketing research
Marketing research reduces uncertainty or error in decision-making. The information collected by conducting marketing research is used for problem solving and decision making in various areas of marketing.
The marketing
research process
Effective marketing research involves five steps shown in Figure:
[pic]
Step 1: Define the Problem and Research Objectives
← This is the introductory phase of the marketing research process.
← It involves a clear and precise understanding of the problem at hand.
← It is crucial that the research team identifies, understands and defines the problem in its entire capacity, as it affects all the subsequent activities involved in the research process.
← Research teams make use of customer feedback, internal and external data reports, sales graphs, purchasing patterns, etc. to come up with an accurate problem definition.
Not all...

...
3. Suppose that a random sample of size 64 is to be selected from a population having [pic] and standard deviation 5.
(a) What are the mean and standard deviation of the [pic] sampling distribution? Can we say that the shape of the distribution is approximately normal? Why or why not? (10 points)
(b) What is the probability that [pic] will be within 0.5 of the population mean? (5 points)
(c) What is the probability that [pic] will differ from the population mean by more than 0.7? (5 points)
4. In the library on a university campus, there is a sign in the elevator that indicates a limit of 16 persons. Furthermore, there is a weight limit of 2500 pounds. Assume that the average weight of students, faculty, and staff on campus is 150 pounds with a standard deviation of 27 pounds, and that the distribution of weights of individuals on campus is approximately normal. If a random sample of 16 persons from the campus is taken:
(a) What is the mean and standard deviation of the [pic] = sample mean distribution? Can we assume the [pic] distribution is normal? Explain. (10 points)
(b) What average weights of for a sample of 16 people will result in the total weight exceeding the weight limit of 2500 pounds? (5 points)
(c) What is the chance that a random sample of 16 persons on the elevator will exceed...