A simple random sample of customers who purchased products at Amazon.com® in the past 3 months were invited by e-mail to respond to the question, “Was our website easy to use, and did you find everything you needed?” About 8% of those contacted responded. Of all customers who purchased products at Amazon.com in the past 3 months, the company predicts the percentage who found the website easy to use and found everything they needed. Identify the type(s) of bias the study has. Explain.