MS 150 Statistics quiz 13 fall 2007 • Name:
Linear regression: On the 15th
of November the physical science students measured current and voltage to determine whether a series of circuits with one, two, and three light bulbs obeyed Ohm's law where Voltage V = current i × resistance R. Their data is shown in the table.
- ______________ Does the relationship between current and voltage appear to be linear, non-linear, or random?
- ______________ Determine the slope of the linear regression (best fit line) for the data.
- ______________ Determine the y-intercept of the linear regression for the data.
- ______________ Determine the correlation coefficient r.
- ______________ Is the correlation positive or negative?
- ______________ Is the correlation none, low/weak, moderate, high/strong, or perfect?
- ______________ Determine the coefficient of determination.
- ______________ What percent in the variation in current "explains" the variation in voltage?
- ______________ What would be the predicted voltage for a current of 0.30 amps?
- ______________ What would be the predicted current for a voltage of 4.5 volts?
|Linear regression statistics|
|Statistic or Parameter||Symbol||Equations||OpenOffice
|Slope||b||=SLOPE(y data; x data)|
|Intercept||a||=INTERCEPT(y data; x data)|
|Correlation||r||=CORREL(y data; x data)|
|Coefficient of Determination||r2||
||=(CORREL(y data; x data))^2