The pre-historic development of agriculture is an active area of research amonganthropologists. The transition from a hunter-gatherer society to an agriculturalsociety is generally assumed to be signaled by an increase in cavities in teeth.Investigators recently studied teeth unearthed in two societies in Colorado:Basketmakers, societies living in small villages, and Post-Basketmakers, societiesliving in above-ground architectures such as pueblos. The investigators wereinterested in whether the shift in shelter was associated with a shift in consumptionfrom hunting (meat) to agriculture (maize). Data on the numbers of individuals withinterproximal (between teeth) cavities are shown in the table below. Inter-proximalcavities tend to occur more among populations subsisting primarily on agriculturalproducts. You may assume that it is reasonable to regard these two samples asrepresentative of teeth from these two populations.
a) Construct and interpret a 90% confidence interval for the difference in populationproportions of individuals with interproximal cavities, Basketmaker - Post-Basketmaker.
b) Interpret the 90% confidence level
c) Based on your results in parts (a) and (b), would you say that a shift inconsumption patterns is a reasonable conclusion on the part of the investigators?
Justify your response with statistical evidence from parts (a) and/or (b).

Question

The pre-historic development of agriculture is an active area of research amonganthropologists. The transition from a hunter-gatherer society to an agriculturalsociety is generally assumed to be signaled by an increase in cavities in teeth.Investigators recently studied teeth unearthed in two societies in Colorado:Basketmakers, societies living in small villages, and Post-Basketmakers, societiesliving in above-ground architectures such as pueblos. The investigators wereinterested in whether the shift in shelter was associated with a shift in consumptionfrom hunting (meat) to agriculture (maize). Data on the numbers of individuals withinterproximal (between teeth) cavities are shown in the table below. Inter-proximalcavities tend to occur more among populations subsisting primarily on agriculturalproducts. You may assume that it is reasonable to regard these two samples asrepresentative of teeth from these two populations.  
a) Construct and interpret a 90% confidence interval for the difference in populationproportions of individuals with interproximal cavities, Basketmaker - Post-Basketmaker.
b) Interpret the 90% confidence level
c) Based on your results in parts (a) and (b), would you say that a shift inconsumption patterns is a reasonable conclusion on the part of the investigators?
Justify your response with statistical evidence from parts (a) and/or (b).

Quizplus · Accepted Answer

The Answer of The pre-historic development of agriculture is an active area of research amonganthropologists. The transition from a hunter-gatherer society to an agriculturalsociety is generally assumed to be signaled by an increase in cavities in teeth.Investigators recently studied teeth unearthed in two societies in Colorado:Basketmakers, societies living in small villages, and Post-Basketmakers, societiesliving in above-ground architectures such as pueblos. The investigators wereinterested in whether the shift in shelter was associated with a shift in consumptionfrom hunting (meat) to agriculture (maize). Data on the numbers of individuals withinterproximal (between teeth) cavities are shown in the table below. Inter-proximalcavities tend to occur more among populations subsisting primarily on agriculturalproducts. You may assume that it is reasonable to regard these two samples asrepresentative of teeth from these two populations.  
a) Construct and interpret a 90% confidence interval for the difference in populationproportions of individuals with interproximal cavities, Basketmaker - Post-Basketmaker.
b) Interpret the 90% confidence level
c) Based on your results in parts (a) and (b), would you say that a shift inconsumption patterns is a reasonable conclusion on the part of the investigators?
Justify your response with statistical evidence from parts (a) and/or (b).

The Pre-Historic Development of Agriculture Is an Active Area of Research