A More Extensive Tabulation of T Critical Values Than What $( \bar { x } - .687 s / \sqrt { 21 } , \bar { x } + 1.725 s / \sqrt { 21 } )$

question 14

Essay

A more extensive tabulation of t critical values than what appears in your text shows that for the t distribution with 20 df, the areas to the right of the values .687, .860, and 1.064 are .25, .20, and .15, respectively. What is the confidence level for each of the following three confidence intervals for the mean μ of a normal population distribution? Which of the three intervals would you recommend be used, and why?
a. $( \bar { x } - .687 s / \sqrt { 21 } , \bar { x } + 1.725 s / \sqrt { 21 } )$
b. $( \bar { x } - .860 s / \sqrt { 21 } , \bar { x } + 1.325 s / \sqrt { 21 } )$
c. $( \bar { x } - 1.064 s / \sqrt { 21 } , \bar { x } + 1.064 s / \sqrt { 21 } )$

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Definitions:

Modularity Position

The view in cognitive science that the mind is composed of distinct, specialized modules, each responsible for different cognitive functions, such as language acquisition or face recognition.

Language Acquisition Device

A hypothetical module of the human brain posited by Noam Chomsky that allows people to understand language structure and acquire language.

Theory of Mind

The ability to attribute mental states—beliefs, intents, desires, emotions, knowledge, etc.—to oneself and to others and to understand that others have beliefs, desires, intentions, and perspectives that are different from one's own.