Year

1. The masses of pennies minted up to 1981 are significantly different than the pennies minted 1983 onwards as evident from the data. The average weight of pennies minted up to 1981 is 3.0796 g where as the average weight of pennies minted 1983 onwards are 2.5010 g.

2. The fit of mean penny masses vs. year for both the plots didnâ€™t result a good one. As per the LINEST fitting data obtained, the plot of mean penny masses vs. year for pennies up to 1981 resulted a fit with R2 = 0.0572 whereas the plot of mean penny masses vs. year for pennies 1983 onwards resulted a fit with R2 = 0.1849, as for both the fits the R2 value is significantly less than 1, we can tell that both the fits are not good one.

3. The slope of the plot of old pennies is not significantly different than the new pennies. The slope of the plot of old pennies is -0.000417 compared to the new pennies which is -0.000629. So, we can tell the slopes are little different from one another not very much.

4. As per the slopes of both the fits we can tell that itâ€™s different from zero but not so much significantly different. For Mean Mass vs. Year plot of pennies up to 1981 gives a straight line with equation Y = -0.000417X + 3.9027, where the slope is -0.000417 and the second plot of Mean Mass vs. Year for pennies 1983-2003 gives a straight line with equation Y = -0.000629X + 3.7553, where slope is -0.000629. So, from the above data we can tell that the slope of both the plot is little different from zero.

5. The average masses of the pennies minted are not exactly same for each year which causes deviation of the slopes of both the plot from zero. This is mainly because of random error of the penny minting machine and due to the fact that random error is an inherent part of our quantized world and this error cannot be eliminated. Again in both the plot the slopes are negative i.e. the Mean Mass of the pennies shows a decreasing trend as the year passes. This may be due to the deposition on metal which increases as their age increases.

A negatively charged sample would be expected to migrate towards th...