The Hill of Tara in Ireland is a place of great archaeologic

The Hill of Tara in Ireland is a place of great archaeological importance. This region has been occupied by people for more than 4,000 years. Geomagnetic surveys detect subsurface anomalies in the earth\'s magnetic field. These surveys have led to many significant archaeological discoveries. After collecting data, the next step is to begin a statistical study. The following data measure magnetic susceptibility (centimeter-gram-second * 10^-6) on two of the main grids of the Hill of Tara Compute sigma x, sigma x^2, sigma y, sigma y^2. Use the results of part (a) to compute the sample mean, variance, and standard deviation for x and for y. Compute a 75% Chebyshev interval around the mean for x values and also for y values. Use the intervals to compare the magnetic susceptibility on the two grids. Higher numbers indicate higher magnetic susceptibiity. However, extreme values, high or low, could mean an anomaly and possiible archaeological treasure. Grid H shows a wider 25% range of values. Grid E shows a wider 75% range of values. Grid E shows a wider 25% range of values. Grid H shows wider 75% range of values. Compute the sample coefficient of variation for each grid.

Solution

d) Coefficint of variation

CV=sd(x)/mean(x) *100

CV=53.95%

CV for Y =49.63%

	X	Y	XY	X^2	Y^2
	21.57	56.06	1209.214	465.2649	3142.724
	10.81	29.27	316.4087	116.8561	856.7329
	8.96	38.67	346.4832	80.2816	1495.369
	27.09	13.76	372.7584	733.8681	189.3376
	24.13	20.34	490.8042	582.2569	413.7156
	36.19	53.24	1926.756	1309.716	2834.498
	10.81	25.98	280.8438	116.8561	674.9604
	10.44	12.35	128.934	108.9936	152.5225
	6.37	42.43	270.2791	40.5769	1800.305
	24.5	44.31	1085.595	600.25	1963.376
	16.73	39.61	662.6753	279.8929	1568.952
	7.48	14.23	106.4404	55.9504	202.4929
	28.94	17.05	493.427	837.5236	290.7025
	35.6	18.93	673.908	1267.36	358.3449
sum	269.62	426.23	8364.527	6595.647	15944.03
means	19.25857	30.445	597.4662	471.1177	1138.859
variance	107.9347	228.2662	251709.3	192214.4	1016963
standard	10.38916	15.10848	501.7064	438.4226	1008.446