
AP#Biology#Chi,square#Practice#Problems#
1. The#age#distribution#of#the#Canadian#population#and#the#age#distribution#of#a#random#sample#of#455#residents#in#the#Red#
Lake#Village#of#the#Northwest#Territories#are#shown#below.##Use#the#chi#square#test#to#determine#if#the#age#distribution#in#
Red#Lake#is#significantly#different#(p#=#0.05)#from#the#general#Canadian#population.#
%#of#Canadian#population#
Observed#number#in#Red#Lake#
#
Conclusion:##D&of&F&=&4&–&1&=&3&;&CV&for&3&D&of&F&=&7.82&;&11.84&>&7.82&;&REJECT&null&hypothesis&;&age&dist.&changed&significantly#
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2. Using#binoculars,#volunteers#observed#feeding#habits#of#a#random#sample#of#320#deer,#as#shown#below.##Use#chi#square#to#
test#the#hypothesis#that#the#natural#distribution#of#plants#fits#the#deer#feeding#pattern.#
Plant#Composition#in#Area#
Observed###of#Deer#Feeding#in#Area#
#
Conclusion:#D&of&F&=&5&–&1&=&4&;&CV&for&4&D&of&F&=&9.49&;&1.32&<&9.49&;&ACCEPT&null&hypothesis&;&plant&distr.&fits&deer&distr.#
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3. The#Fish#and#Game#Department#stocked#Lake#Lulu#with#fish#in#the#following#proportions:#30%#catfish,#15%#bass,#40%#
bluegill,#and#15%#pike.##Five#years#later,#they#sampled#500#fish#in#the#lake#to#see#if#the#distribution#of#fish#had#changed,#as#
shown#below.##Use#the#chi#square#test#to#determine#if#the#distribution#of#fish#changed#significantly#(p#=#0.05)#in#the#5,year#
interval.#
Catfish#=#120,#Bass#=#85,#Bluegill#=#220,#Pike#=#75#
#
Conclusion:#D&of&F&=&4&–&1&=&3&;&CV&for&3&D&of&F&=&7.82&;&9.33&>&7.82&;&REJECT&null&hypothesis&;&fish&distr.&changed&signif.&In&5&yrs.#