A state biologist is investigating whether the proportion of frogs in a certain area that are bullfrogs has increased in the past ten years. The proportion ten years ago was estimated to be 0.20. From a recent random sample of 150 frogs in the area, 36 are bullfrogs. The biologist will conduct a test of H0:p=0.20 versus Ha:p>0.20. Which of the following is the test statistic for the appropriate test?
a. z=0.20−0.24(0.24)(0.76)150
b. z=0.20−0.24(0.20)(0.80)150
c. z=0.24−0.20(0.24)(0.76)150
d. z=0.24−0.20(0.20)(0.80)150
e. z=0.24−0.20(0.20)(0.80)150