The Results of a Survey Showed That, on Average, Children

question 75

Essay

The results of a survey showed that, on average, children spend 5.6 hours at PlayStation per week. Suppose that the standard deviation is 1.7 hours and that the number of hours at PlayStation follows a bell-shaped distribution.
a. Use the empirical rule to calculate the percentage of children who spend between 2.2 and 9 hours at PlayStation per week.
b. What is the z-value for a child who spends 7.5 hours at PlayStation per week?
c. What is the z-value for a child who spends 4.5 hours at PlayStation per week?

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Definitions:

Deformation

The process of change in the shape or size of rocks in response to stress, leading to folding, faulting, or shearing.

Subsidence

The gradual sinking or settling of the Earth's surface, which can result from natural processes such as erosion or human activities like mining.

Uplift

The vertical elevation of the Earth's surface due to natural processes like tectonic movements, leading to mountain building and other geological features.

Crustal Thickness

The measure of the depth of the Earth's crust, varying from the thinnest beneath the oceans to the thickest under high mountains.