Excel formulas and functions: calculating costs, applying percentage increases, counting, and finding minimum values.

Here are the solutions to your questions:

Figure 1

• i) Write a formula to calculate the total cost of rice. (1 mark) The number of units for rice is in cell B3, and the cost per unit is in cell C3.

  $$=\text{B3} \times \text{C3}$$

  The formula is $\boxed{=\text{B3}*\text{C3}}$.

• ii) The prices of all items increased by 10% and the value 10% is placed in cell B8. Using cell addresses with absolute referencing only, write a formula to calculate the new unit price of salt. (2 marks) The original cost per unit for salt is in cell C5. The increase percentage is in cell B8. $=\text{C5} \times (1 + \text{\$B\$8})$ The formula is \boxed{=\text{C5}*(1+\text{\B$8})}$.

• iii) Write a function to display the number of cells in which the cost per unit is equal to 110. (2 marks) The cost per unit values are in the range C2:C5.

  $$=\text{COUNTIF}(\text{C2}:\text{C5}, 110)$$

  The function is $\boxed{=\text{COUNTIF}(\text{C2}:\text{C5},110)}$.

• iv) Write a function to display the least total cost for all items. (2 marks) Assuming the total costs are calculated in cells D2:D5.

  $$=\text{MIN}(\text{D2}:\text{D5})$$

  The function is $\boxed{=\text{MIN}(\text{D2}:\text{D5})}$.

19. (a) What is meant by each of the following terms as used in the inter-net?

• i) Surf: To browse or navigate through various websites and web pages on the internet.
• ii) Uploading: The process of transferring data from a local computer or device to a remote server or another computer over a network.
• iii) Inbox: A designated folder or section within an email client where incoming email messages are stored for a user.

19. (b) A school has set up its network using wireless technology to link computers. State three problems that the school is likely to experience when using this technology. (3 marks)

• Security risks: Wireless networks are more vulnerable to unauthorized access and data interception compared to wired networks.
• Interference: Wireless signals can be disrupted by other electronic devices, physical obstacles, or other wireless networks, leading to slower speeds or dropped connections.
• Limited range and coverage: Wireless signals have a finite range, which may result in dead spots or require multiple access points to cover the entire school effectively.

19. (c) List three ways by which parents can protect their children from accessing inappropriate content from the internet. (3 marks)

• Using parental control software or browser settings to block access to specific websites or content categories.
• Placing computers in common areas of the house where usage can be easily monitored.
• Educating children about internet safety and the importance of reporting inappropriate content or interactions.

19. (d) Explain three problems associated with using e-mail technology for communication. (3 marks)

• Spam and junk mail: Users often receive a large volume of unsolicited emails, which can clutter inboxes, waste time, and pose security risks like phishing.
• Security vulnerabilities: Emails can be intercepted, contain malicious attachments (viruses), or be used for phishing scams, leading to data breaches or identity theft.
• Misinterpretation: The absence of non-verbal cues in email communication can lead to misunderstandings or misinterpretations of tone and intent.

20. (a) Explain three reasons why an organization may need to change to a new computerized system. (6 marks)

• Increased efficiency and productivity: An old system may be slow, manual, or inefficient, and a new system can automate tasks, streamline workflows, and improve overall operational speed.
• Outdated technology and lack of support: The existing system might be based on obsolete technology, making it difficult to maintain, find compatible hardware, or receive vendor support.
• Enhanced functionality and features: A new system can offer advanced capabilities, better reporting tools, or improved integration with other business processes, meeting evolving organizational needs.

20. (b) State why each of the following is important in system documentation.

• i) Sample data: Sample data is crucial for testing the system to ensure it functions correctly and produces expected results. It also serves as a training aid for new users to understand data entry and processing.
• ii) Output reports: Output reports are important for verifying the accuracy of the system's processing and for providing critical information to management for decision-making and performance evaluation.

20. (c) Name the tools used for data storage in each of the following methods of data processing.

• i) Manual:
  • Files/Folders (physical paper documents)
  • Ledgers/Registers
• ii) Electronic:
  • Hard Disk Drives (HDDs)
  • Solid State Drives (SSDs)

20. (d) A teacher manages students' records by storing daily attendance information in a file called register and students' personal records such as year of birth and home address in a file called students.

• i) Identify the types of computer files named above. (2 marks)
  • Register file: Transaction file
  • Students file: Master file
• ii) Give a characteristic of data held in each file. (2 marks)
  • Register file: Data is dynamic and frequently updated (e.g., daily attendance records).
  • Students file: Data is relatively static and changes infrequently (e.g., permanent personal details).
• iii) Name the field that should be used to link the two files. (1 mark) A Student ID or Admission Number.