QUESTION 1
Briefly explain
(a) What type of survey method the researcher could use and why?
(b) What sampling method could the researcher use to select his/her sample and why?
(c) What are the variables the researcher should consider collecting data for the purpose of the analysis and why? Identify the data type(s) for the variables.
(d) What kind of issues the researcher may face in this data collection?
QUESTION 2
First, the researcher wishes to use the graphical descriptive methods to present the data.
(a) He suggests using 10 classes such as class intervals 0-6, 6-12, 12-18, ... for one variable and class intervals 0-30000, 30000-60000, 60000-90000, .... , for the other variable. Explain how he could have decided on the number of classes as 10 and the above class intervals.
(b) Use appropriate BIN values to draw a histogram for each variable and comment on the shape of the two distributions.
(c) Use an appropriate plot to investigate the relationship between the two variables. Briefly explain the selection of each variable on the X and Y axes and why? On the same plot, fit a linear trend line including the equation and the coefficient of determination.
QUESTION 3
Second, the researcher wishes to use the numerical descriptive measures to summarize the data.
(a) Prepare a numerical summary report about the data on the two variables the researcher has considered by including the summary measures, mean, median, range, variance, standard deviation, smallest and largest values and the three quartiles, for each variable.
(b) Use five of the above summary measures to represent the summary information in a box plot for each variable. Draw the box plot (either by hand or using Data Analysis Plus).
(c) Compute a numerical summary measure to measure the strength of the relationship between the two variables. Interpret this value.
QUESTION 4
The researcher considers using regression analysis to establish a linear relationship between the two variables.
(a) What is his dependent variable and independent variable? Why?
(b) Estimate a simple linear regression model and present the estimated linear equation. Interpret the coefficient estimates of the linear relationship.
(c) Interpret the coefficient of determination, R-squared (R2) value.
QUESTION 5
A shopping mall estimates the probability distribution of the number of stores mall customers actually enter (X), as shown below:
(a) Find the value of k.
(b) Find the mean of number of stores entered.
(c) Find the standard deviation of the number of stores entered.