Assignment 2_Bubble chart
This bubble chart visualizes the correlation between make cost, selling price, and profit percentage for various car brands. The data, sourced from `profits.csv`, is rendered as an interactive SVG using D3 v7, where bubble size encodes profit percentage and color distinguishes car brands. Implemented with `d3.csv`, `d3.scaleLinear`, and `d3.scaleOrdinal`, the chart displays axes for selling price and cost, with a legend for profit percentage and brand colors. Hovering over a bubble triggers a tooltip showing the brand name, supported by custom `showTooltip`, `moveTooltip`, and `hideTooltip` functions on `mouseover`, `mousemove`, and `mouseleave` events.