Problem 1RE
Walmart Stores Currently, there are 4227 Walmart stores in the United States and another 3210 stores outside of the United States.
a. Are the numbers of Walmart stores discrete or continuous?
b. What is the level of measurement for the numbers of Walmart stores in different years? (nominal, ordinal, interval, ratio)
c. If a survey is conducted by randomly selecting 10 customers in eveiy Walmart store, what type of sampling is used? (random, systematic, convenience, stratified, cluster)
d. If a survey is conducted by randomly selecting 20 Walmart stores and interviewing all of the employees at the selected stores, what type of sampling is used? (random, systematic, convenience, stratified, cluster)
e. What is wrong with surveying customer satisfaction by mailing questionnaires to 10,000 randomly selected customers?
Answer :
Step 1 of 1 :
Given, there are 4227 Walmart stores in the United States and another 3210 stores outside of the United States.
a)
Discrete: A discrete function is a function with distinct and separate values. This means that the values of the functions are not connected with each other.
For example, a discrete function can equal 1 or 2 but not 1.5.
Continuous: A continuous function, on the other hand, is a function that can take on any number within a certain interval.
For example, if at one point, a continuous function is 1 and 2 at another point, then this continuous function will definitely be 1.5 at yet another point.
The given example is Discrete, Because we are able to count the number of Wal-Mart stores.
b)
ratio:Ratio scales are the ultimate nirvana when it comes to measurement scales because they tell us about the order, they tell us the exact value between units, AND they also have an absolute zero–which allows for a wide range of both descriptive and inferential statistics to be applied.
Ratio because we can establish an absolute zero.
c)
Stratified sampling : the researcher divides the population into separate groups, called strata. Then, a probability sample (often a simple random sample ) is drawn from each group.
Strata : the total population is divided into non-overlapping subgroups
Every walmart store serves as its own stratum because the customers at each store may have varying opinions.
Hence, we can use Stratified sampling method.
d)
Cluster sampling : the researcher divides the population into separate groups, called clusters. Then, a simple random sample of clusters is selected from the population.
Each walmart store serves as its own cluster, with a representative sample in each store.
Then, people are randomly selected from each store and surveyed.
Hence, we can use Cluster sampling method.
e) This is a voluntary sample which introduces bias. Maybe only customers who are satisfied or customers who are dissatisfied will participate in the sample, misrepresenting overall sample size and not producing a representative sample.
