document.write( "Question 1155291: A person claims to have ESP (extrasensory perception). A coin is tossed 30 times, and each time, the person is asked to predict in advance whether the coin will land heads or tails. The person predicts correctly 60% of the time (i.e., on 18 tosses). What is the probability of being correct 18 or more times by pure guessing \n" ); document.write( "

Algebra.Com's Answer #777870 by ikleyn(52803) $\"\"$ $\"About$

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document.write( "It is  P =  = 1 -  = 1 - BINOM.DIST(17,30,0.6,TRUE) = 1 - 0.4215 = 0.5785.    ANSWER\r\n" );
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document.write( "I used the probability 0.6 to guess correctly and 0.4 to guess incorrectly (according to the condition)\r\n" );
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\n" ); document.write( "\n" ); document.write( "I used Excel function BINOM.DIST to quickly calculate the expression.\r
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\n" ); document.write( "\n" ); document.write( "On Excel function BINOM.DIST, see its description everywhere, for example\r
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\n" ); document.write( "\n" ); document.write( "https://support.office.com/en-us/article/binom-dist-function-c5ae37b6-f39c-4be2-94c2-509a1480770c\r
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