Greece has faced a severe economic crisis since the end of 2009. A Gallup poll surveyed 1,000 randomly sampled Greeks in 2011 and found that 25% of them said they would rate their lives poorly enough to be considered "suffering". 

(a) Describe the population parameter of interest. What is the value of the point estimate of this parameter? 

(b) Check if the conditions required for constructing a confidence interval based on these data are met. 

(c) Construct a 95% confidence interval for the proportion of Greeks who are "suffering". 

(d) Without doing any calculations, describe what would happen to the confidence interval if we decided to use a higher confidence level. 

(e) Without doing any calculations, describe what would happen to the confidence interval if we used a larger sample.