Question 1

Jeffrey is a real estate agent who wishes to study the relationship between the selling price of a house and its size (measured in feet) in Manhattan. He develops a simple linear regression model as seen below. What is the slope of the model? Houseprice = 95.5 + 0.25 (square feet) + 13
A)95.5
B) 0.25
C)13
D) 4.5

Accepted Answer

The slope of the above model is 0.25.
Key Takeaway: A simple linear regression model contains three components: intercept, slope, and error term. The slope of the model is multiplied by the independent variable (size of the house) in the equation in order to calculate the dependent variable (house price).

Question 2

The following is a multiple regression model. What do the regression coefficients b₁ and b₂ represent? Y _i= b₀ + b₁X_1i + b₂X_2i +e_i A)slopes of independent variables B)slopes of dependent variables C)random error term D)graph intercept

Accepted Answer

Regression coefficients b1 and b2 in a linear regression model represent slopes of the independent variables under study. Key Takeaway: Multiple regression analysis is used to study the effect of two or more independent variables on the dependent variable. In the linear regression model, b₁ and b₂ are calculated slopes of the independent variables. For example, if a marketing researchers is studying income and level of education as independent variables, their slopes in the analysis would be represented as b1 and b2.

Question 3

State officials wish to study those factors that affect adherence to job rehabilitation after a job-related injury. The propose to study two particular factors: the extent of previous injury and the worker's educational level. What is this type of research design called?
A)simple linear regression
B)multiple regression
C)ANOVA
D)chi-square

Accepted Answer

Multiple regression analysis is used to study the effect of two or more independent (or explanatory) variables on the dependent variable.
Key Takeaway: Multiple regression analysis is used to study the effect of two or more independent variables on the dependent variable. In this example, the extent of previous injury and the workerâ€™s educational level are both independent variables that are hypothesized to affect the dependent variable (adherence to job rehabilitation).

Question 4

The given numbers are daily groundwater elevation readings from a monitoring well taken during a month experiencing snowmelt and extended rainfall events.
7.6, 7.7, 4.3, 5.9, 5.0, 10.5, 7.7, 9.5, 12.0, 12.6, 6.5, 8.3, 8.2, 13.2, 12.6, 13.6, 14.1, 13.5, 11.5, 12.0, 10.4, 10.8, 13.1, 12.5, 10.4, 13.0, 14.1, 15.1
What is the sample variance of these groundwater elevation readings?
A) 8.764
B) 9.089
C) 10.56
D) None of the above

Accepted Answer

The sample variance of the groundwater elevation readings is 9.089. Use the sample variance (s²) equation s² = ?(sample value - sample mean)²/(number of samples-1) Where Number of samples = 28 Sample mean = ?(sample values)/number of samples = 295.7/28 = 10.56 ?(sample value - sample mean)² = (7.6-10.56)²+(7.7-10.56)² = 245.4 s² = 245.4/27 = 9.089

Question 5

Rogers Telemarketing provides direct marketing campaigns for small and medium sized businesses. To select populations for survey purposes, the company seeks data sources such as phone books and consumer lists. These sources are also referred to as:
A)sampling medium
B)sampling lists
C)sampling frame
D)sampling methodology

Accepted Answer

A Sampling Frame provides data sources for research.
Key Takeaway: A sampling frame is a list of common elements that allows access to a desired population for study. Think of sampling frames as data sources such as phone directories, geographic maps, or customer/client directories. Other examples of sampling frames are electoral databases where there are lists of voters and their contact information, or university enrollment databases for lists of current and past students.

Quiz 5: Statistics

Jeffrey is a real estate agent who wishes to study the relationship between the selling price of a house and its size (measured in feet) in Manhattan. He develops a simple linear regression model as seen below. What is the slope of the model? Houseprice = 95.5 + 0.25 (square feet) + 13

The following is a multiple regression model. What do the regression coefficients b1 and b2 represent? Y i= b0 + b1X1i + b2X2i +ei

State officials wish to study those factors that affect adherence to job rehabilitation after a job-related injury. The propose to study two particular factors: the extent of previous injury and the worker's educational level. What is this type of research design called?

Rogers Telemarketing provides direct marketing campaigns for small and medium sized businesses. To select populations for survey purposes, the company seeks data sources such as phone books and consumer lists. These sources are also referred to as:

The following is a multiple regression model. What do the regression coefficients b₁ and b₂ represent? Y _i= b₀ + b₁X_1i + b₂X_2i +e_i