Given that $X$ is a binomial random variable, the binomial probability $P(X \geq x)$ is approximated by the area under a normal curve to the right of
A. $x-1$
B. $x+1$
C. $x-0.5$
D. $x+0.5$

If the standard error of the sampling distribution of the sample proportion is 0.0229 for samples of size 400, then the population proportion must be either
A. 0.3 or 0.7
B. 0.2 or 0.8
C. 0.4 or 0.6
D. 0.5 or 0.5