In 10000 independent tosses of a coin it landed heads 5400 t
In 10,000 independent tosses of a coin, it landed heads 5400 times. Is it reasonable to assume that the coin is not fair? Explain.
Solution
The test hypothesis:
Ho: p=0.5 (i.e. null hypothesis)
Ha: p not equal to 0.5 (i.e. alternative hypothesis)
The test statistic is
Z=(phat-p)/sqrt(p*(1-p)/n)
=(5400/10000-0.5)/sqrt(0.5*0.5/10000)
=8
It is a two-tailed test.
Assume that the significant level a=0.05
The critical values are Z(0.025) = -1.96 or 1.96 (from standard normal table)
The rejection regions are if Z<-1.96 or Z>1.96, we reject the null hypothesis.
Since Z=8 is larger than 1.96, we reject the null hypothesis.
So we can conclude that the coin is not fair
