Jóhannes plans to examine the salary of a middle manager in a large company. He collects data on salaries and how long they have been employed as middle managers with the aim of creating a model that can predict salaries with work experience. Jóhannes has a total of data from 20 randomly selected middle managers who range from being new to the job to having 12 years of work experience. Jóhannes started by drawing the data and sees that the relationship is linear. He also calculates some light quantities that can be seen below: Change Average Standard Deviation Wages Work Experience He also calculated the correlation coefficient between wages and work experience and obtained r = 0.82. Change average standard deviation salary 761041 238473 work experience 5.65 3.71 a. Find an equal regression line for John's model. b. What is the explanatory power of the model and what does it tell us? c. How much does a middle manager's salary increase in five years according to the model? d. Use the model to predict the salary of a middle manager with 20 years of work experience. Is the forecast reliable? Justify.
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.
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