Local Walmart store is upgrading its legacy database system. The new database system will be used to manage the supple chain and transactional data, including products, vendors, customers and invoices. Design a relational database model for this system. Some of the business rules are as follows: a product can have many vendors, and a vendor can supply many products. A customer can have many invoices, and each invoice is associated with only one customer. Each invoice may contain many different products, and a product can appear on many invoices (For example, a TV model can be purchased by many customers and therefore appears on multiple invoices). A. Start with drawing the Entity-Relationship Model. List all entities, attributes, and relationships among entities.
B. Draw the relational model.

The “rule of 72” is used to approximate the time required for prices to double due to inflation. if the inflation rate is r%, then the rule of 72 estimates that prices will double in 72/r years. for instance, at an inflation rate of 6%, prices double in about 72/6 or 12 years. write a program to test the accuracy of this rule. for each interest rate from 1% to 20%, the program should display the rounded value of 72/r and the actual number of years required for prices to double at an r% inflation rate. (assume prices increase at the end of each year.)

Brian wants to conduct an online search with a certain phrase. he intends to use the words books that belong to the 1800s in his search. how should he use the word that in his search?

This question involves a class named textfile that represents a text file. public class textfile { private string filename; private string filename; private arraylist words; // constructors not shown // postcondition: returns the number of bytes in this file public int filesize() { } // precondition: 0 < = index < words.size() // postcondition: removes numwords words from the words arraylist beginning at // index. public void deletewords(int index, int numwords) { } // precondition: 0 < = index < = words.size() // postcondition: adds elements from newwords array to words arraylist beginning // at index. pub lic voidaddwords(int index, string[] newwords) { } // other methods not shown } complete the filesize() method. the filesize() is computed in bytes. in a text file, each character in each word counts as one byte. in addition, there is a space in between each word in the words arraylist, and each of those spaces also counts as one byte. for example, suppose the words arraylist stores the following words: { mary had a little lamb; its fleece was white as snow. } the filesize() method would compute 4 + 3 + 1 + 6 + 5 + 4 + 6 + 3 + 5 + 2 + 5 as the sum of the lengths of each string in the arraylist. the value returned would be this sum plus 10, because there would also be 10 spaces in between the 11 words. complete the filesize() method below: // postcondition: returns the number of bytes in this file public int filesize() { }