Assignment 1

README.md

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-# Statistical-IT
-Statistical IT
+Njenga Stephen Wairegi
+SCM222-0763/2025
+SMA 2102: IT FOR STATISTICS
+1.	INTRODUCTION TO IT FOR STATISTICS
+•	Data is raw facts.
+•	IT ( Information Technology) refers to use of technological tools to store, process, transmit and manage information or processed data.
+•	For Statistics; it is referred to as the application of computer systems and statistical software to make data handling faster, more accurate and easier to interpret (collect, store, process, analyze and present)
+Role of IT
+•	Data analysis
+	Convert raw data to information.
+	Systematic process of inspecting and interpreting data to come up with meaningful conclusions and support informed decision.
+	Programs used; SPSS, EXCEL, R, PYTHON.
+•	Data collection
+•	Data storage 
+•	Data processing
+•	Data presentation
+Role of IT for Statistics in Society
+•	Financial Impact:
+	Enhances employability and addressing skills gap.
+	Vocational training and apprenticeship.
+	Financial literacy and economic resilience.
+	Reduced financial vulnerability.
+	Economic participation and growth.
+•	Social Impact:
+	Reduced economic dependency.
+	Diverse talent pipeline.
+	Community Integration.
+•	Data collection and enhancement.
+•	Supports planning and policy making.
+•	Enables storage and management.
+•	Boosts research and innovation.
+
+2.	Fundamentals of Computer Operations.
+•	Computer is an electronic device that inputs data, process it and give out information.
+•	Computers are made hardware (physical parts) and software.
+Components of a computer
+	Output devices
+	Input devices
+	CPU (Central processed unit) – process instuctions/data:
+	ALU – performs calculations
+	Control Unit – direct co-ordinates
+	Register – small storage……
+	Motherboard – connects all components.
+	Memory – RAM (temporary) ROM (permanent)
+	Secondary: USB, Hard drive, SSD, CD ( compact disk), Memory card.
+Software – set of instructions that tell a computer what to do.
+	System – controls computer hardware and provides a platform for application software e.g Windows
+	Application – programs designed to perform specific tasks e.g Microsoft Word
+Basic Operations of a Computer
+•	Input – receive data/ input data
+•	Processing – process statistical formular, performing calc/data manipulation.
+•	Storage – saving data permanently or temporarily.
+•	Output – displaying; display results using charts and graphs.
+•	Control – managing entire process; use tools like Excel, SPSS, R, Python. 
+•	IPO Cycle: Input – process – Output
+Computer Operation Cycle (Machine Cycle)
+•	Fetch – get instruction from memory.
+•	Decode – Interpret the instruction.
+•	Execute – perform the operation.
+•	Store – save result in memory or register. 
+3.	Computer Hardware Basics
+Computer hardware refers to the physical components of a computer system. It includes input devices like the keyboard and mouse, output devices such as the monitor and printer, and internal components found in the system unit. Key internal parts are the CPU, which processes data, RAM for temporary storage, the motherboard that connects all components, and storage devices like HDDs and SSDs for long-term data storage. Other hardware includes the power supply, which provides electricity, and communication devices like network cards that enable connectivity. Together, these parts allow the computer to input, process, store, and output information.
+4.	Computer Software Basics
+•	Software is a collection of programs, instructions and data that tell a computer what to do.
+•	It is intangible – you cannot touch it like hardware.
+•	Two types of software:
+a)	System Software
+•	This is software that managesand controls the hardware so that other software can run, it includes:
+I.	Operating Systems (OS) – e.g., Windows, Linux, macOS, Android.
+II.	Functions: manages files, memory, processes, hardware, and provides the user interface.
+III.	Utility Programs – perform maintenance tasks.
+IV.	Examples: antivirus, disk cleanup, file compression, backup tools.
+V.	Device Drivers – help hardware communicate with the OS.
+Examples: printer driver, keyboard driver, graphics driver.
+B. Application Software
+These are programs used to perform specific tasks for the user.
+Categories:
+I.	General-purpose software – Word processors (Word), Spreadsheets (Excel), Browsers (Chrome).
+II.	Special-purpose software – Designed for a specific task.
+Examples: payroll systems, school management systems, banking software.
+III.	Customized software – Created to meet the unique needs of an organization.
+
+Differences Between System and Application Software
+System Software                                                                                      Application Software
+Controls/manages hardware                                                            Helps users perform tasks
+Runs automatically when computer starts                                     Runs when user opens it
+Example: OS                                                                                          Example: Word, Chrome
+Software Acquisition Methods
+Ways to get software:
+•	Purchase – buying a license.
+•	Freeware – free to use.
+•	Shareware – free trial then paid.
+•	Open-source – source code available for modification.
+•	Custom development – software built for specific needs.
+Software Licensing
+A license is a legal agreement that states how software can be used.
+Types:
+•	Single-user license
+•	Multi-user license
+•	Site license
+•	Free and open-source license
+•	Proprietary license
+Software Installation and Updates
+Installation puts the program onto the computer.
+Updates fix bugs, add features, and improve security.
+Importance of Software
+•	Enables communication with hardware.
+•	Helps users complete tasks.
+•	Provides a platform for applications to run.
+•	Enhances productivity and efficiency.
+
+5.	DATA AND DATA FILES 
+1. Data
+Raw, unprocessed facts (numbers, text, images, sound).
+Has no meaning until processed into information.
+2. Types of Data
+Numeric: numbers used in calculations.
+Text/Alphanumeric: letters, digits, symbols.
+Boolean: TRUE/FALSE values.
+Multimedia: pictures, audio, video.
+
+3. Data Representation
+Computers use binary (0s and 1s) to represent all data.
+Units: bit> byte> KB> MB> GB >TB.
+Bit (short for binary digit)
+The smallest unit of digital data.
+It can have only one of two values: 0 or 1.
+Example: A single light switch (on = 1, off = 0) represents 1 bit.
+Byte
+A group of 8 bits.
+One byte can represent 256 different values (2⁸ = 256), which is enough to store one text character (like the letter "A") using ASCII/Unicode.
+Example: The letter "A" in ASCII is 01000001 in binary → that’s 1 byte (8 bits).
+KB (Kilobyte)
+Approximately 1,000 bytes in everyday/decimals use (used by storage manufacturers),
+or exactly 1,024 bytes in technical/binary use (used by computers).
+Most of the time in school and exams:
+1 KB = 1,024 bytes
+MB (Megabyte)
+Approximately 1,000,000 bytes (decimal),
+or exactly 1,048,576 bytes in binary (1,024 × 1,024).
+Again, in most school/technical contexts:
+1 MB = 1,024 KB = 1,048,576 bytesText uses ASCII/Unicode; images use pixels; audio uses sampled values.
+4. Files
+A file is a named collection of related data stored on a device.
+Has a name, type, size, and location.
+5. Types of Files
+Data files: documents, images, audio, video, spreadsheets.
+Program files: executable instructions (.exe, drivers, system files).
+6. File Management
+Creating, saving, renaming, moving, copying, deleting, backing up files.
+Organizing files into folders helps easy access and safety         
+7. Data Security & Integrity
+Security: protect data using passwords, antivirus, permissions.
+Integrity: ensure data stays accurate and uncorrupted.
+Use backups to prevent loss.
+8.	Relationship
+Data > processed by a program >becomes information > stored as file
+6. Disk Storage Fundamentals 
+1. Types of Disk Storage
+a) Magnetic Storage
+Hard Disk Drive (HDD), Floppy disks
+Characteristics: Large capacity, cheaper per GB, slower, mechanical parts (prone to physical damage)
+b) Solid-State Storage
+SSD, USB flash drives, memory cards
+Characteristics: Very fast, no moving parts, durable/shock-resistant, more expensive per GB
+c) Optical Storage
+CDs, DVDs, Blu-ray
+Characteristics: Cheap, portable, good for backups/distribution, low capacity, easily scratched
+2. How Disk Storage Works
+HDD: Spinning platters coated with magnetic material, read/write heads move over tracks and sectors
+SSD: Uses NAND flash memory cells; no moving parts, extremely fast access
+Optical: Laser reads/reflects off pits (0) and lands (1) burned into disc surface
+3. Key Terms
+Track: Circular path on a platter
+Sector: Smallest addressable storage unit (usually 512 bytes or 4 KB)
+Cylinder: Same track number across multiple platters
+Access Time: Time taken to locate and retrieve data
+Capacity: Total storage size (e.g., GB, TB)
+4. Why Disk Storage Matters
+Permanent (non-volatile) data retention
+Essential for storing OS, applications, databases, and user files
+Directly affects system performance (SSD >> HDD speed)
+5. Disk Performance Factors
+Seek Time: Time for read/write head to move to correct track (HDD only)
+Rotational Latency: Time for platter to rotate to correct sector (HDD only)
+Transfer Rate: Speed of actual data read/write once positioned
+6. Advantages of Disk Storage
+Large capacity (especially HDD/SSD)
+Permanent/non-volatile storage
+Faster than tape storage
+Supports all file types
+7. Disadvantages
+HDD: Slow, mechanical failure risk, noise/vibration
+SSD: Higher cost per GB, limited write cycles
+Optical: Very slow, low capacity, easily damaged by scratches
+8. Common Uses
+Operating systems and applications
+Databases and large files
+Backups (external drives, optical discs, cloud)
+Media storage (photos, videos, music)
+9. File Systems (organize & manage data on disks)
+FAT32: Old, compatible, max 4 GB file size
+NTFS: Windows standard, secure, journaling, large files
+exFAT: Good for flash drives, supports large files, cross-platform
+ext4: Linux standard, reliable, journaling
+APFS: Modern macOS/iOS file system, fast, encrypted
+10. Disk Maintenance Best Practices
+Disk Cleanup: Remove temporary files, junk, recycle bin
+Defragmentation: Reorganize fragmented files (only needed for HDDs; SSDs should NOT be defragged)
+Regular Backups: Use external drives, optical media, or cloud storage.