Hi there!
Set up our hypotheses:
H0: p= 1/2Ha: p > 1/2
Let's compute the test statistic:
z = (phat - p)/sqrt(p*(1-p)/N)
Plug in our values:
phat = 38/60
p = 0.5
N = 60 samples
z = (38/60 - 0.5)/sqrt(0.5*(1-0.5)/60)
z = 2.06559
Using a z table (http://davidmlane.com/hyperstat/z_table.html), at the 0.10 level, with one tail, the critical value is: 1.2816. Since our test statistic is higher than that, we reject the null hypothesis, and conclude that the coin IS biased.
Using the same z table, we can get the p value of z = 2.06559:
p = 0.019434
Our p value is lower than the 0.10 level, so again, we reject the null hypothesis and conclude that the coin is biased
Let me know if you have any questions. If not, thanks for accepting!
-Scott
MIT Graduate
College degree in math... proficient in all levels -- from algebra to calculus