Final answer:
We derive the rate of change or slope from two points on the graph, representing the hourly follower increase. The y-intercept indicates Zara's initial follower count. The linear equation for the situation is y = mx + b, where m is the slope and b is the y-intercept.
Step-by-step explanation:
To find the rate of change, we need two points from the graph. The rate of change, often called the slope, represents how many followers Zara gains per hour. Without the actual graph, we can't calculate the specific rate but it's found by taking the difference in the number of followers and dividing it by the difference in hours.
The y-intercept is the point where the line crosses the y-axis and represents Zara's initial number of followers before the promotion began. Again, without the graph, it's impossible to provide the exact y-intercept value.
The formula for a linear equation is typically expressed as y = mx + b where m is the slope and b is the y-intercept. If we had the slope and y-intercept, we could write the equation representing Zara's social media followers over time.