:10. The proportion of 1's in a 0-1 box is unknown.  John
believes that it is 1/2.  Mary thinks that there are more 0's
than 1's.  They agree to set ip a statistical test.  The null
hypothesis is that the proportion of 1's is 1/2.  The alternative
hypothesis is that the proportion of 1's in the box is less than
1/2.  100 tickets are drawn from the box (with replacement).  40
of them are 1's, so the observed significance level of the test
is the chance that the number of 1's in the sample is less than
40, the chance being computed under the assumption that the null
hypothesis is true.  This chance is closest to

 	
 a. 10% 
 	
 b. 5% 
 	
 c. 2.5% 
 	
 d. 1% 
 	
 e. .5%