/**
 * Given the revenue and cost of a marketing campaign, calculate the return on investment (ROI).
 */
fun calculateCampaignRoi(revenue: Double, cost: Double): Double {

    // Calculate the ROI using the formula: (revenue - cost) / cost * 100
    val roi = (revenue - cost) / cost * 100
    return roi
}
/**
 * Given the revenue and cost of a marketing campaign, calculate the return on investment (ROI).
 */
fun calculateCampaignRoi(revenue: Double, cost: Double): Double {
/**
 * Given the revenue and cost of a marketing campaign, calculate the return on investment (ROI).
 */
fun calculateCampaignRoi(revenue: Double, cost: Double): Double {

    // Calculate the ROI using the formula: (revenue - cost) / cost * 100
    val roi = (revenue - cost) / cost * 100
    return roi
}