MGSC 291 Farnoush exam questions with answers

MGSC 291 Farnoush exam questions with|\ |\ |\ |\ |\




answers
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<- - CORRECT ANSWERS ✔✔"is defined to be"
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ls() - CORRECT ANSWERS ✔✔Reminds you of all stored objects
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== - CORRECT ANSWERS ✔✔equal to
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!= - CORRECT ANSWERS ✔✔not
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< - CORRECT ANSWERS ✔✔less than
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<= - CORRECT ANSWERS ✔✔less than or equal to
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> - CORRECT ANSWERS ✔✔greater than
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>= - CORRECT ANSWERS ✔✔greater than or equal to
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| - CORRECT ANSWERS ✔✔or
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& - CORRECT ANSWERS ✔✔and
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, vec4==10 - CORRECT ANSWERS ✔✔Returns: [1] TRUE FALSE |\ |\ |\ |\ |\ |\ |\ |\


FALSE FALSE |\




dataFrameName <- read.csv("filename.csv", strings = T) - |\ |\ |\ |\ |\ |\ |\


CORRECT ANSWERS ✔✔Reads data files into R |\ |\ |\ |\ |\ |\




getwd() - CORRECT ANSWERS ✔✔identifies the current working
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directory


dataFrameName$columnName - CORRECT ANSWERS ✔✔ACCESS |\ |\ |\ |\ |\


A COLUMN IN A DATA FRAME
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mean(cars$price[cars$fuelsystem == "mpfi"]) - CORRECT |\ |\ |\ |\ |\


ANSWERS ✔✔prints the average prices for cars with multi-point
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fuel injection
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If R returns with + - CORRECT ANSWERS ✔✔you have likely not
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closed out aparenthesis or quotation mark.
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If the mean function returns "NA" - CORRECT ANSWERS ✔✔there
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are missing values
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mean() - CORRECT ANSWERS ✔✔average
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str() - CORRECT ANSWERS ✔✔Examines data structure and type
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sum() - CORRECT ANSWERS ✔✔sum
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