Question

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 (Reference: Tara: An Archaeological Survey by Conor Newman, Royal Irish Academy, Dublin). Grid E: x variable 37.82 24.13 31.90 18.95 6.37 19.32 12.66 38.19 7.85 25.98 21.54 11.18 24.50 34.86 Grid H: y variable 41.96 32.09 47.60 44.78 28.33 45.25 51.36 41.02 55.59 53.71 31.62 53.71 24.10 30.21

(a) Compute Σx, Σx²,  Σy, Σy². (Enter your answers to 2 decimal places.)

Σx		Σx2
Σy		Σy2

(b) Use the results of part (a) to compute the sample mean, variance, and standard deviation for x and for y. (Enter your answers to 2 decimal places.)

	x	y
x
s2
s

(c) Compute a 75% Chebyshev interval around the mean for x values and also for y values. (Enter your answers to 2 decimal places.)

	x	y
Lower Limit
Upper Limit

(d) Compute the sample coefficient of variation for each grid. (Enter your answers to one decimal place.)

	x	y
CV	%	%

Answer 1