Final answer:
The sampling distribution of the sample proportion is approximately normal. The probability of observing a sample proportion as large as or larger than 0.70 can be calculated using the sampling distribution and finding the area under the curve beyond 0.70.
Step-by-step explanation:
(a) The sampling distribution of the sample proportion is approximately normal with a mean equal to the true population proportion, which in this case is 0.70, and a standard deviation equal to the square root of (p * (1-p) / n), where p is the population proportion and n is the sample size.
(b) To calculate the probability of observing a sample proportion as large as or larger than p=0.70, we can use the sampling distribution and find the area under the curve beyond 0.70. This can be done using a statistical software or a Z-table. The calculated probability is the p-value, which indicates the likelihood of observing a result as extreme or more extreme than the observed value under the assumption that the proportion is actually 0.65.