Statistics Functions | HP 15c Scientific instruction

56 Section 4: Statistics Functions

Linear Estimation. With the statistics accumulated, an estimated value for y, denoted ŷ, can be calculated by keying in a proposed value for x and pressing ´j.

An Estimated value for x (denoted xˆ ) can be calculated as follows:

1.Press ´L.

2.Key in the known y-value.

3.Press ® - ® ÷.

Correlation Coefficient. Both linear regression and linear estimation presume that the relationship between the x and y data values can be approximated by a linear function. The correlation coefficient, r, is a determination of how closely your data fit a straight line. The range is -1 ≤ r

≤1, with -1 representing a perfectly negative correlation and +1 representing a perfectly positive correlation.

Note that if you do not key in a value for x before executing ´j, the number previously in the X-register will be used (usually yielding a meaningless value for ŷ).

Example: What if 70 kg of nitrogen fertilizer were applied to the rice field? Predict the grain yield based on Farmer’s accumulated statistics. Because the correlation coefficient is automatically included in the calculation, you can view how closely the data fit a straight line by pressing ® after the y prediction appears in the display.

Image 56

HP 15c Scientific manual Statistics Functions

Contents

HP-15C Owner’s Handbook HP Part Number 00015-90001 Edition 2.4, Sep Legal Notice Introduction Contents Contents Display and Continuous Memory Program Editing Program Branching and Controls Subroutines Calculating With Matrices Indirect Display ControlCalculating With Complex Numbers Numerical Integration Contents Appendix a Error Conditions Appendix C Memory AllocationAppendix D a Detailed Look at Appendix E a Detailed Look at f Contents Appendix F Batteries Function Summary and IndexProgramming Summary and Index Subject Index HP-15C Problem Solver Quick Look at Manual Solutions To Compute Keystrokes Display Programmed Solutions Keystrokes Display KeystrokesDisplay 001-42,21,11002 003 004 005 006 007 008 009 8313 300.51 HP-15C a Problem Solver Part l HP-15C Fundamentals Power On and Off Getting StartedKeyboard Operation Section Prefix Keys Changing SignsKeying in Exponents I O m ´ P I l F T s ? t H b Clear Keys Clears only the last digit Display Clearing ` and −Digit entry not terminated Calculations One-Number FunctionsTwo-Number Functions 6532 17 + 26.0000 22.0000 500013.0000 78.0000 Numeric Functions Number Alteration Functions One-Number Functions General Functions Pressing Calculates Trigonometric OperationsTime and Angle Conversions Degrees/Radians Conversions 7069Radians 40.5000 Logarithmic Functions Hyperbolic Functions Power Function Two-Number FunctionsPercentages To Calculate Keystrokes Display Polar and Rectangular Coordinate Conversions Enters the base number the priceCalculates 3% of $15.76 the tax Polar Conversion. Pressing Keystrokes Display Automatic Memory Stack Last X, and Data Storage Automatic Memory Stack Stack ManipulationAutomatic Memory Stack Registers Always displayed Lost Stack Manipulation FunctionsMemory Stack, Last X, and Data Storage Lost Last X Register and K 287.000022.2481 12.9000 20.6475 Calculator Functions and the Stack13.9 + Order of Entry and the v Key +15 X15 Nested Calculations 7 +65.0000 69.0000 Arithmetic Calculations With Constants 5 ‛15 Keys 000 Keystrokes Display Growth factor1000 Storage Register Operations Storing and Recalling Numbers322.5000 520.8750 Clearing Data Storage Registers Storage and Recall Arithmetic For storage arithmetic For recall arithmetic Problems Overflow and Underflow24 l-0 15.0000 Memory Stack, Last X, and Data Storage 60.0000 Statistics FunctionsProbability Calculations Random Number Generator 270,725.00005764 3422 Accumulating Statistics Registers Register Contents 20.00 40.00 60.00 80.00 Kg per hectare Metric tons per Hectare, y20 z 61v 40 z 7.21 60 z 7.78 80 z l Σy2 Correcting Accumulated Statistics 20 w 20 z 40.00 MeanStandard Deviation Linear Regression 31.62Standard deviation about the mean nitrogen Application Linear Estimation and Correlation Coefficient Statistics Functions Other Applications 70 ´j Fixed Decimal Display Display Continuous MemoryDisplay Control Scientific Notation Display Engineering Notation Display234568 234567 Round-Off Error Special DisplaysMantissa Display Annunciators Error Display Digit Separators12,345.67 12.345.6700 Status Low-Power IndicationContinuous Memory Resetting Continuous Memory Page Part ll HP-15C Programming Programming Basics MechanicsCreating a Program Loading a Program Programming Basics ´b a 002 003 004 005 006 007 008 Intermediate Program StopsRunning a Program How to Enter Data 300.51 300.51 ´A Program Memory Radius, r Height, h Base Area Volume Surface Area Totals 002 004 005007-44,40 010 Or G a Instruction Coding Further InformationProgram Instructions Memory Configuration Keycode 25 second row, fifth key Initial Memory Configuration 60 ´ m% Program Boundaries ´ m %19 ´ m% 19.0000 ´bA ´b3 End of memory Unexpected Program StopsAbbreviated Key Sequences User Mode Polynomial Expressions and Horners Method¤ @ y ∕ LOG % Nonprogrammable Functions 001-42,21,12002 003 004 005 006 007 008 009 0000 12,691.0000 Problems Program Editing Moving to a Line in Program Memory Inserting Program Lines ExamplesDeleting Program Lines Or use Â Single-Step Operations Line Position ÂholdRelease Result Insertions and Deletions Initializing Calculator Status PV 1 + i n Interest+ i n 100 270 ´bA D ´4 O0 2* O1 2÷ * ´ ´ l0 l1 ´r * n Program Branching Controls Branching Conditional Tests Test Flags  n will clear flag number n Example Branching and Looping 010-45,20 013-43,30014 016-44,40 Example Flags Formula is 002-43 004-42,21,15005-43, 4 006-42,21 Go to 250.000048.0000 10,698.3049 Looping Conditional Branching System Flags Flags 8 Program Branching and Controls Subroutines Go To Subroutine and ReturnSubroutine Execution ´b.1 Subroutine Limits 000 001- ´b9 002- R003- O0 004 ´ b.4 ´b.5 Subroutine Return Nested Subroutines 106 Index Register Loop ControlV and % Keys Indirect Program Control With the Index Register Program Loop ControlIndex Register Storage and Recall Index Register and Loop Control Indirect Branching With Index Register ArithmeticExchanging the X-Register Loop Control With Counters I and e Indirect Flag Control WithIndirect Display Format Control With Nnnnn x x x y y 5 0 0 Start count at zero Count by twos Count up to Examples Register Operations IterationsStoring and Recalling Keystrokes Display 12.3456 Storage Register Arithmetic Example Loop Control with eExchanging the X-Register Loop control number in R2 −− 011- 42012-42, 5 013- 22 64.8420 0000 50.0000 Example Display Format Control15 O Index Register Contents Indirect Display Control Index Register and Loop Control 118 Part lll HP-15C Advanced Functions Complex Stack and Complex Mode Calculating With Complex NumbersCreating the Complex Stack 120 Entering Complex Numbers Deactivating Complex ModeComplex Numbers and the Stack ´ % hold 8.0000 release Z 8 Y 7 X Keys Stack Lift in Complex Mode Manipulating the Real and Imaginary Stacks Clearing a Complex Number Or other operation Continue with any operation − 4 v Continue with any operation 0000 17.0000 144.0000 Entering Complex Numbers with −. The clearing functions −´ %hold release Entering a Real Number Followed by another number Entering a Pure Imaginary Number ´ Continue with any operation Operations With Complex Numbers Storing and Recalling Complex Numbers´ O L 2 ´ ¤x N o ∕ @ a + * ÷ y 2000 70000428 0491 Polar and Rectangular Coordinate Conversions Complex Results from Real Numbers5708 ´ % hold Release1.5708 Cos θ + i sin θ = re iθ Polar + ib = ∠ θ + 3.1434 84522981 352.0000 872.00002361 4721 For Further Information Calculating With Matrices 138 Keystrokes Display Deactivates Complex Mode = A-1B Matrix Dimensions Running11.2887 2496 Dimensioning a Matrix Number Rows Columns Displaying Matrix Dimensions Changing Matrix Dimensions´mA Keystrokes l B Display Storing and Recalling Matrix Elements Storing and Recalling All Elements in Order ⎡ a Checking and Changing Matrix Elements Individually Keystrokes Display Matrix Descriptors Matrix OperationsStoring a Number in All Elements of a Matrix Result Matrix Copying a Matrix One-Matrix Operations Calculating with Matrices Scalar Operations LB b Elements of Result Matrix LA a LB b 2 LA a 2 Arithmetic OperationsKeystrokes Display Subtracts 1 from the elements Matrix Multiplication = AT B Keystrokes Display l a a Solving the Equation AX = B 24 OA 240086 OA 8600 274 OB 233 OB 331 OB 120.32 OB 112.96 OB 151.36 OB ´Á Calculating the Residual Week Cabbage kg 186 141 215 Broccoli kg 116 Using Matrices in LU Form Calculations With Complex Matrices Storing the Elements of a Complex Matrix Then Z can be represented in the calculator by Pressing Transforms Into = ⎢ LA a Complex Transformations Between ZP and Z Inverting a Complex Matrix Multiplying Complex Matrices ´ a Keystrokes lA lB Display Displays descriptor of matrix a ´U lC LC lC lC lC lC lC lC ´U Solving the Complex Equation AX = B ZZ −1 AX = B 200.0000 170.0000 0372 13110437 1543 Calculating with Matrices Miscellaneous Operations Involving Matrices Using a Matrix Element With Register OperationsUsing Matrix Descriptors in the Index Register Stack Operation for Matrix Calculations Conditional Tests on Matrix Descriptors Calculating with Matrices Using Matrix Operations in a Program ´m a Summary of Matrix FunctionsKeystrokes Results Calculates residual in result matrix For Further Information 180 UsingFinding the Roots An Equation Finding the Roots of an Equation Clear program memory ´b0 001-42,21002 003 005 006 007 Finding the Roots of an Equation Desired root Keystrokes ¥ ´ bA000 001-42,21,11 003 004 5000 1 e t Brings another t-valueInto X-register 200 t When No Root Is Found 000 001-42,21 002 003 004 005 Error Choosing Initial Estimates Label 003 004 005 007 X + 8008 009 6 x + 8 Finding the Roots of an Equation Using in a Program Restriction on the Use Memory Requirements 194 Using fNumerical Integration 002 003 004 4040 1416 7652 Begin subroutine with a label 4401 3825$ ÷ 6054 Accuracy of f ´ i ´ f 8826 7091 Using f in a Program 382 Memory Requirements Error Conditions Error 0 Improper Mathematics OperationAppendix a 205 Error 1 Improper Matrix Operation Error 2 Improper Statistics Operation Error 3 Improper Register Number or Matrix Element Error 4 Improper Line Number or Label CallError 5 Subroutine Level Too Deep Error 6 Improper Flag Number Pr Error Power Error Stack Lift Last X Register Digit Entry TerminationStack Lift Appendix B Disabling Operations Enabling Operations Stack Stack Enabled. disabled 53.1301 No stack Lift Neutral OperationsAppendix B Stack Lift and the Last X Register Keys Nnn Clear u ¥ Last X Register \ k + H ∆ \ h ÷ À P* q r c ‘ / N z ∕ P\ o j Memory Allocation Memory SpaceAppendix C Registers Appendix C Memory Allocation M % Function Memory ReallocationMemory Status W 19 ´ m Restrictions on Reallocation´m% 1.0000 Whold 1 64 Program Memory Automatic Program Memory Reallocation Memory Requirements for the Advanced Functions Two-Byte Program InstructionsIf executed Together Appendix C Memory Allocation Detailed Look at How WorksAppendix D 220 Appendix D a Detailed Look at Accuracy of the Root X4 = 000 1718 006 007 008 009 010-43,30 011 012-43,30 013 0681 Interpreting Results´ v B − 45 For 0 x Test for x range Branch for x ≥3x 45x 2 + End subroutine 000.0000 Initial estimates1358 Possible root Appendix D a Detailed Look at ´ b.0 001-42,21,.0 002 003 004 005 Bring x-value into X-register007 008 009 010 013 014 015 016 017 018 10 v ´ ‛ 20 Error 0000 1250 5626 Finding Several Roots Fx = xx a3 = 002 003 004 005 006 007 6667 Same initial estimates Second rootStores root for deflation Deflated function value Deflation for third root Limiting the Estimation Time Specifying a Tolerance For Advanced InformationCounting Iterations Detailed Look at f How f WorksAppendix E 240 Accuracy, Uncertainty, and Calculation Time X = π1 0π cos4θ − x sinθ dθ 0000 1416 ´ i ´ f Keystrokes Display Return approximation to ´ Clear u HoldKeystrokes ´ i Display ´ f ´ Clear u hold 7858 7807 Uncertainty and the Display Format Functions values for example Δx = 0.5×10−n ×10m = aδx dxb = ab 0.5×10−n + m x dx Conditions That Could Cause Incorrect Results ∞ xe− xdx 001-42,21 002- 1 003 004 005 Appendix E a Detailed Look at f Appendix E a Detailed Look at f Conditions That Prolong Calculation Time Keys lower limit into Keys upper limit intoApproximation to integral Uncertainty Appendix E a Detailed Look at f Obtaining the Current Approximation to an Integral For Advanced Information Low-Power Indication Installing New BatteriesBatteries Batteries Appendix F Batteries Verifying Proper Operation Self-Tests 2.C 3.H Function Summary and Index Complex FunctionsConversions Digit Entry Display Control Index Register ControlLogarithmic Exponential Functions Mantissa. Pressing 146 MathematicsMatrix Functions To XT Number AlterationTo ZP page164 Percentage ProbabilityStack Manipulation Clear u Statistics Storage Trigonometry Programming Summary and Index 269 Programming Summary and Index Subject Index 271 Subject Index Subject Index Subject Index Subject Index Subject Index Subject Index Subject Index Subject Index Subject Index Subject Index Subject Index Subject Index Modifications Product Regulatory Environment InformationFederal Communications Commission Notice Canadian Notice Avis Canadien European Union Regulatory Notice Body number is inserted between CE