A shoe company takes a random sample of 400 customers who visited their website last month and found that 275 of them actually purchased shoes. Determine the lower limit of a 95% confidence interval (z = 1.96) for the proportion of those people that will purchase shoes if they visit the website. Round the answer to 4 decimal places.

a. 0.5354 b. 0.7272 c. 0.5210 d. 0.6420 e. 0.3995