Electronic Arts Data Analyst interview questions

How you would count “top peaks” and “bottom peaks” in a list of radioactivity values, based on these rules: - A value is a top peak if it is at least 5 units higher than both neighbors. - A value is a bottom peak if it is at least 5 units lower than both neighbors. - The first and last items in the list can never be peaks.

How would you describe linear regression?