Question

The graph shows a scatter plot for a set of data. Scatter plot with x-axis labeled year and y-axis labeled megawatts. The 18 points plotted are 1982 and 76.2, 1983 and 50.6, 1984 and 46.4, 1985 and 35.5, 1986 and 31.1, 1987 and 26.1, 1988 and 21, 1989 and 15.6, 1990 and 14.9, 1991 and 13.8, 1992 and 13, 1993 and 13, 1994 and 10, 1995 and 10, 1996 and 7, 1997 and 6.9, 1998 and 6.6, and 1999 and 6.

What type of correlation exists? Is the model linear or non-linear?
The graph shows a negative correlation, and it is a linear model.
The graph shows a positive correlation, and it is a linear model.
The graph shows a negative correlation, and it is a non-linear model.
The graph shows a positive correlation, and it is a non-linear model.

Answer 1

(c) The graph shows a negative correlation, and it is a non-linear model.

Explanation:

You want to know the sign of the correlation and whether it is best modeled by a linear or nonlinear function for the data shown in the graph.

Sign

The dependent variable generally gets smaller when the independent variable gets larger. This means the correlation is negative.

Linearity

A straight line could be used to model the data, but it looks like an inverse relation or an exponential decay (nonlinear model) may give a better fit.

A nonlinear model would best fit this data.

The best choice is ...

The graph shows a negative correlation, and it is a non-linear model, choice C.

<95141404393>