A restaurant conducted a survey to determine whether customers are satisfied with its food delivery service by clicking “Yes” or “No” on an online form shared with them. From a random sample of 440 responses, it found that 278 customers selected

“Yes.”

a. Find the standard error to estimate the population proportion of “Yes” responses.

b. Find the sampling error to estimate the population proportion of “Yes” responses with 95% confidence level.

c. Estimate the proportion of “Yes” responses with 98% confidence level.