A coin was flipped 60 times and came up heads 38 times. (a) At the .10 level of significance, is the coin biased toward heads? Show your decision rule and calculations. (b) Calculate a p-value and interpret it.
I have both Excel and Megastat, but have no idea how to use either program although I am aware these types of problems can be done in either program.
I have both Excel and Megastat, but have no idea how to use either program although I am aware these types of problems can be done in either program.
-
Forget the programs - this is straightforward application of the normal approximation to the binomial distribution. Expected number of heads = n p = 60 (0.5)= 30; std dev = sqrt( np(1-p))=
sqrt( 60(0.5) (1-0.5)) = 3.873. So this result is (38-30)/3.873= 2.07 standard deviations above the expected result, and is thus statistically significant at the .10 level of significance.
From normal table, this has a p- value of about .03.
sqrt( 60(0.5) (1-0.5)) = 3.873. So this result is (38-30)/3.873= 2.07 standard deviations above the expected result, and is thus statistically significant at the .10 level of significance.
From normal table, this has a p- value of about .03.