Studyfin
✨ Sign up free
Hi there! Today we will explore how things change together and learn to read the stories hidden in graphs.
In math, we look at how two different things change at the same time. We call these pairs bivariate data, like comparing study hours to test scores.
A scatterplot uses dots to show this data. When the dots form a clear path, we can draw a straight trend line to show the general direction.
Not all data is linear. Linear data forms a straight line pattern, while non-linear data curves or spreads out with no clear path.
The slope of our trend line tells us the rate of change. It shows how much the vertical value changes for every step we take to the right.
A student tracks their savings over 4 weeks. In Week 1 they have $20, and in Week 3 they have $40. Let's find the rate of change per week.
- Identify the two data points as pairs: (1, 20) and (3, 40).
- Find the change in savings (vertical change): 40 minus 20 equals 20 dollars.
- Find the change in weeks (horizontal change): 3 minus 1 equals 2 weeks.
- Divide the savings change by the time change: 20 divided by 2 equals 10.
- The rate of change is 10 dollars per week.
