The proportion of items in a population that possess a specific attribute is known to be 0.70.
a. If a simple random sample of size n = 100 is selected and the proportion of items in the sample that contain the attribute of interest is 0.65, what is the sampling error?
b. Referring to part a, what is the probability that a sample of size 100 would have a sample proportion of 0.65 or less if the population proportion is 0.70?