Question Two The following table gives the experience (in years) and the number of computers sold during the previous three months by seven salespersons. Experience ( years) 4 12 10 16 Computer sold {unit) 19 42 28 31 39 35 21 1) Determine both dependent and independent variables, and explain the expected relationship between them. 2) Calculate the correlation coefficient comment on the results. |Page1 3) Estimates the simple regression model and comment on the estimated coefficients. 4) Predict the number of computers sold during the past three months by salespersons with eleven years of experience.
Correlation
Correlation defines a relationship between two independent variables. It tells the degree to which variables move in relation to each other. When two sets of data are related to each other, there is a correlation between them.
Linear Correlation
A correlation is used to determine the relationships between numerical and categorical variables. In other words, it is an indicator of how things are connected to one another. The correlation analysis is the study of how variables are related.
Regression Analysis
Regression analysis is a statistical method in which it estimates the relationship between a dependent variable and one or more independent variable. In simple terms dependent variable is called as outcome variable and independent variable is called as predictors. Regression analysis is one of the methods to find the trends in data. The independent variable used in Regression analysis is named Predictor variable. It offers data of an associated dependent variable regarding a particular outcome.
![Formula Sheet
E,(x; – X)²
s2
%3D
n - 1
CV =
X 100
E(x; - X)2
S =
n - 1
-
Ztab
Z =
First quartile location = 1/4 (n+1)
Third quartile location= 3/4 (n+1)
Value of quartile= start + ratio * distance
ηΣ xy - ΣxΣy
Bo = Ÿ – ß,X
r =
VIηΣ x2-(Σ x)?] [n Σ y? - (Σν)?1
ηΣ xy -ΣxΣy
η Σ x2 - (Σ x)2
Simple linear regression model
Yi = Bo + B1ס + Uj
Where i = 1,2,...n
Estimated simple linear regression model
P = Bo + B,X,
%3D
Critical Values |Ztabl
0.001
0.005
0.010
0.025
0.050
0.100
|Ztabl
3.090
2.576
2.326
1.960
1.645
1.282
|Page 4](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F0bb82111-dea9-4ff2-8edd-493bcb33bf32%2F32057ddb-0243-4c64-acfa-2f28fe4fbe50%2Fsrabgbp_processed.jpeg&w=3840&q=75)
Step by step
Solved in 3 steps
