All codes should be written in racket

Question 1: IPv4 Address

Internet Protocol (IP) addresses are commonly used as identifiers of computer network interfaces for exchanging messages on the Internet or an intranet. Two major versions are being used today, version 4 and version 6, called IPv4 and IPv6, respectively. These versions and Internet standards are developed by the Internet Engineering Task Force (IETF) and published as RFC documents. Nowadays, to ensure compatibility, IPv4 and IPv6 co-exist on a computer usually built-in with an operating system called the "dual-stack" approach.

A simple but important task is checking whether an IP address is valid. Let us take a look at the IPv4 address as a starting point. An IPv4 address can be expressed in 4 decimal numbers separated by dots, as shown below, where each number can be any integer between 0 and 255 (inclusive).

192.168.1.16

Write a function valid-ipv4addr? that consumes four numbers, indicating four decimal numbers (in the order from left to right) of an IPv4 address, and produces true if and only if all four numbers are integers between 0 and 255 inclusive, and false otherwise.