A coin was flipped 13 times and came up heads 11 times A Cal

A coin was flipped 13 times and came up heads 11 times

A) Calculate a p-value for the observed sample outcome, using the normal distribution. (Round your z-value to two decimal places. Round your answer to 4 decimal places.)

B) Use Excel to calculate the binomial probability P(X ? 11 | n = 13, ? = 0.50) = 1 ? P(X ? 10 | n = 13, ? = 0.50). (Round your answer to 4 decimal places.)

Solution

(a) The test statisitc is

Z=(phat-p)/sqrt(p*(1-p)/n)

=(11/13-0.5)/sqrt(0.5*0.5/13)

=2.50

It is a right-tailed test.

So the p-value= P(Z>2.50) =0.0062 (from standard normal table)

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(b) The probability is 0.0112