export interface CostProjection {
    trend: 'up' | 'down' | 'stable';
    slope: number;
    rSquared: number;
    weekly: PeriodProjection;
    monthly: PeriodProjection;
    dailyHistory: DayPoint[];
}
export interface PeriodProjection {
    projected: number;
    lower80: number;
    upper80: number;
    daysWithData: number;
    costSoFar: number;
    avgPerDay: number;
}
export interface DayPoint {
    date: string;
    dayIndex: number;
    cost: number;
    fitted: number | null;
}
export declare function computeProjection(days?: number): CostProjection;
export declare function formatProjection(p: CostProjection): string;