Testing the hypothesis?

Question

Suppose you want to check whether a coin is fair or not.  You flip the coin 100 times and get 34 tails.  Test the appropriate hypothesis at .

Round your answers to three decimal places.

(a). Without rounding any interim calculations, compute the test statistic: 

(b). Using your answer from part (a), compute the p-value: 

Answer 1

the standard deviation is sqrt(p * (1-p)/n )

sqrt( 0.5 * 0.5 / 100) = sqrt( 1/40) = 1/20

the test stat is ( 0.5 - 0.34) / 1/20 = 20 ( 0.16) = 3.2

this exceeds the alpha value threshold at 99% confidence.

There is statistical evidence that the coin is biased