SPSS 2020 Computing P1

READ THESE INSTRUCTIONS FIRST Write your name, class, index number in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Approved calculators are allowed. Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question. You should show all your working. The total number of marks for this paper is 80. Parent’s Signature : ____________________________ Date: ____________________________ Remarks (if any) : For Examiner’s Use Marks /80 Total % This document consists of 11 printed pages including this page. ST. PATRICK'S SCHOOL PRELIMINARY EXAMINATIONS 2020 SECONDARY 4 EXPRESS NAME CLASS INDEX NUMBER COMPUTING Paper 1 Written 7155/01 20 August 2020 2 h Candidates answer on the Question Paper. No Additional Materials are required.

2 1 (a) Convert the binary number 0101 1111 into its hexadecimal value. [1] (b) Convert the positive whole denary number 462 into a 12-bit binary number. Answer: [2] (c) Describe how the hexadecimal number 8A is converted into its denary value. Give the denary value in your answer. Description: Denary value: [4]

3 2 The following diagram shows five network terms and six descriptions. Draw a line from each network device to its best description. Network Devices Description Bridge A device that constructs a single network by connecting two similar networks together Router A device responsible for modulation and demodulation Network Interface Card (NIC) A device that provides the hardware interface to enable the transfer of data between a device and a network. Modem A device that extends the distance a signal can travel Hub A device that forwards packets between separate networks A device that transmits received packets to all connected devices [5]

4 3 The following pseudo-code algorithm validates the age of a user. 1 2 3 4 5 6 7 8 9 10 11 is_valid = False no_of_users = 0 CURRENT_YEAR = 2020 WHILE is_valid = False OUTPUT “Enter your birth year: ” INPUT birth_year IF CURRENT_YEAR – birth_year >= 18 THEN is_valid = True no_of_users = no_of_users + 1 ENDIF ENDWHILE (a) The algorithm is tested using the following three numbers as input: 2006, 2000. Complete the trace table for the algorithm. birth_year is_valid no_of_users [3] (b) State whether is_valid is a variable or a constant. Give a reason for your choice. [2] (c) Identify the data validation technique used in the algorithm. [1] (d) Identify two other data validation checks. 1: 2: [2]

5 (e) The algorithm is tested with data for normal conditions. Identify two other test case conditions that could be used to test the algorithm. For each condition, give an example of test data for this algorithm. Test case condition 1: Test data 1: Test case condition 2: Test data 2: [4] 4 A government agency has asked your company to create an app for citizens to access all government services. • The app will display a menu that lets the user login or register for an account. • If the user registers for an account, the user must fill up a particulars form. • If the user logs in, he/she will have to pass a few authentication measures before he/she can be granted access. • Once access is given, the user will be able to select a list of government services. • The user can also access his/her email inbox to view/send messages from/to various government services. • The user can log out from the app at any time. (a) Identify five modules that can be decomposed from the problem. Module 1: Module 2: Module 3: Module 4: Module 5: [5]

6 (b) For the login module, state the input, output and process that are required. Input: Output: Process: [3] 5 (a) Draw a logic circuit to represent the following Boolean statement. Do not simplify the statement. X = (NOT A OR (B NOR C)) AND (A NAND C) [5] X A B C

7 (b) Complete the following truth table for the Boolean statement: X = (NOT A OR (B NOR C)) AND (A NAND C) A B C Working space X 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 [4] 6 An e-commerce company uses technology to train its staff. (a) Give three social benefits to the staff of using technology to upgrade their skills. 1: 2: 3: [3] (b) One negative impact of using technology in a company is that its sensitive data can be compromised by cyber-attackers. State two types of cyberattacks. 1: 2: [2] (c) Describe two ways in which the company can adopt to ensure the security and integrity of its customers’ data. 1: 2: [4]

8 7 Alice has a $65 000 loan to buy a car. The loan is repaid over 3 years. The interest rate is 10% per year. She has a spreadsheet to keep track of the repayments and the amount she owes. A B C D E 1 Initial Loan $65,000.00 Total Paid to Date $4,194.74 2 Interest Rate 10% Amount Owed $71,310.00 3 Loan Length (months) 36 Number of Payments Made 2 4 Monthly Payment -$2,097.37 5 Total to Pay $75,505.22 6 7 Date Amount Paid 8 01/01/2020 $2,097.37 9 01/02/2020 $2,097.37 10 (a) Identify the most appropriate data type for the following cell references. A1: A8: B1: [3] (b) The cell B4 shows the monthly payment amount. Identify the most appropriate function to use in cell B4, if the interest rate and monthly payment amount remain the same. [1] (c) The cell E1 shows the total amount that Alice has paid to date. The payments are entered in cells B8 to B43. Identify the most efficient function to use in cell E1. [1] (d) The formula in cell E3 calculates the number of payments made. Identify the most appropriate function to use in cell E3. [1]

9 8 This section of program pseudo-code asks user for 100 Body Mass Index (BMI) numbers between 18.5 and 40. It checks that the numbers are in the correct range, and stores them in an array. It counts how many of the numbers are larger than or equal to 27.5 and then outputs the result. 1 2 3 4 5 6 7 8 9 10 11 count = 0 array = [] FOR num = 1 TO 100 INPUT 'Enter the BMI: ', BMI WHILE BMI = 18.5 AND BMI = 40 INPUT 'Out of range BMI. Enter value between 18.5 and 40', BMI ENDWHILE array[100] = BMI IF BMI >= 27.5 THEN count = count + 1 NEXT PRINT num, ' BMIs were larger than or equal to 27.5.' There are three errors in this code. Locate the errors and suggest a correction. Error 1: Correction: Error 2: Correction: Error 3: Correction: [6] 9 Complete the following sentences by filling in the missing words. (a) ……………………………………. is a network device that provides a connection between wireless devices up to 100 metres away and can connect to wired networks. (b) ……………………………………. stores large amounts of data that will not be lost when power supply is interrupted. (c) ……………………………………. is a device or computer program that prevents unauthorised access to or from a private network. (d) ……………………………………. is a network of computing devices connected within a small geograp