How to access JavaScript files in the assets folder in the angular-cli scripts

I'm using angular-cli. I'm getting a 404 error for scripts.bundle.js file.

This might be with the file, which I've added in the scripts of angular-cli as below. How to access the JavaScript files, which are there in the assets folder in the angular-cli scripts.

"apps": [{
    "root": "src",
    "outDir": "dist",
    "assets": [
        "assets",
        "favicon.ico"
    ],
    "index": "index.html",
    "main": "main.ts",
    "polyfills": "polyfills.ts",
    "test": "test.ts",
    "tsconfig": "tsconfig.app.json",
    "testTsconfig": "tsconfig.spec.json",
    "prefix": "app",
    "styles": [
        "../node_modules/bootstrap/dist/css/bootstrap.min.css",
        "styles.scss"
    ],
    "scripts": [
        "assets/js/slick.min.js",
        "assets/js/bootstrap.min.js",
        "assets/js/jquery.placeholder.min.js",
        "assets/js/jquery-3.2.1.min.js",
        "assets/js/plugins.js",
        "assets/js/popper.min.js"
    ],
    "environmentSource": "environments/environment.ts",
    "environments": {
        "dev": "environments/environment.ts",
        "prod": "environments/environment.prod.ts"
    }
}],