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Statistical Process Control Charts and Business Value Metrics

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Customer Value: (Quality, Time, Flexibility, Customer Experience, Innovation) / Price

Sustainability Paradigms: Economic (Viable, Equitable), Environment (Viable, Bearable), Social (Bearable, Equitable)

- Efficiency (Optimization), Differentiator (Innovation), Driver (Motivation) | - Audits (Assess Sustainability Performance)


Table 7.3: Factors for Calculating Three-Sigma Limits for the X (Bar) Chart and R-Chart

Size of Sample (n)Factor for UCL and LCL for X (Bar) Charts (A2​)Factor for LCL for R-Charts (D3​)Factor for UCL for R-Charts (D4​)
21.88003.267
31.02302.575
40.72902.282
50.57702.115
60.48302.004
70.4190.0761.924
80.3730.1361.864
90.3370.1841.816
100.3080.2231.777

*A sample is out of control if its value falls below the LCL or above the UCL*

... Continue reading "Statistical Process Control Charts and Business Value Metrics" »

Corporate Taxation: Distributions, Redemptions, and Tax Accounting

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Corporate Distribution Layers

Distributions are applied in the following order: Accumulated E&P + Current E&P, then basis, then the remainder is treated as capital gain.

  • No Dividend: If there is no E&P, reduce current E&P first. Negative AEP still distributes E&P.
  • Offset: Half of current E&P is lost to offset AEP before distribution.

Property Distributions

Recognize gains, but not losses.

  • Dividend: FMV - Liabilities
  • Basis: FMV
  • Gains: FMV - Tax Basis

Distribution Table

The amount from CEP is calculated as: (Period distribution / Total distribution) * CEP. AEP is applied to the remainder, then to stock basis.

Stock Distributions and Redemptions

  • Stock Distribution: Proportionate distributions are nontaxable and do not reduce E&
... Continue reading "Corporate Taxation: Distributions, Redemptions, and Tax Accounting" »

5 hr 20 min 20 sec corresponds to a longitude difference of

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lim x->0 sinx/x = 1 | H.A.: compare degrees | V.A.: denom = 0 | Continuous if: f(a), lim, equal

DERIVATIVES: (x^n)'=nx^(n-1), (e^x)'=e^x, (a^x)'=a^x ln a, (lnx)'=1/x | (uv)'=u'v+uv', (u/v)'=(u'v-uv')/v^2 |chain: (f(g(x)))'=f'(g(x))g'(x)

TRIG DERIVATIVES: (sin)'=cos, (cos)'=-sin, (tan)'=sec^2 | (sec)'=sec·tan, (csc)'=-csc·cot, (cot)'=-csc^2

CRITICAL POINTS:f'=0 or DNE ⇒ crit pt | f'>0 inc | f'<0 dec | f''>0 conc up | f''<0 conc down | inflec = f'' signchange

INTEGRATION: ∫x^n dx = x^(n+1)/(n+1)+C | ∫e^x dx = e^x+C | ∫a^x dx = a^x/ln a+C | ∫1/x dx = ln|x|+C | ∫sin x dx

= -cos x+C | ∫cos x dx = sin x+C

FTC: Part 1: d/dx ∫_a^x f(t) dt = f(x) | Part 2: ∫_a^b f(x) dx = F(b)-F(a)

AREA & VOLUME: A = ∫_a^b (top - bot)... Continue reading "5 hr 20 min 20 sec corresponds to a longitude difference of" »

Multivariable Calculus and Vector Analysis Formulas

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Gradient: \nabla f = \langle f_x,\ f_y,\ f_z\rangle Directional derivative (unit vector u): D_uf = \nabla f\cdot u Unit direction from A→B: u = \frac{B-A}{\|B-A\|} Tangent plane to z=f(x,y): z - z_0 = f_x(x_0,y_0)(x-x_0)+f_y(x_0,y_0)(y-y_0) Critical points: Solve f_x=0, f_y=0. D = f_{xx}f_{yy} - (f_{xy})^2 Min if D>0,f_{xx}>0. Max if D>0,f_{xx}<0. Saddle if D<0.

General double integral: Type I (y inner): \int_a^b \int_{g_1(x)}^{g_2(x)} f\, dy\, dx

Type II (x inner):

\int_c^d \int_{h_1(y)}^{h_2(y)} f\, dx\, dy

Polar:

x = r\cos\theta,\ y=r\sin\theta,\ dA=r\,dr\,d\theta

Circle: 0\le r\le R.

Line y=mx → \theta=\arctan m.

Region must be continuous in θ.


🔷

3. TRIPLE INTEGRALS

Cylindrical:

x=r\cos\theta,\ y=r\sin\theta,\ dV=r\,dz\,dr\,... Continue reading "Multivariable Calculus and Vector Analysis Formulas" »

Number Theory Problems: GCD, Congruences, and Fermat Numbers

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1. Find the GCD of (143, 227)

The Euclidean Algorithm is used to find the Greatest Common Divisor (GCD) of two integers by repeatedly dividing the larger number by the smaller number until the remainder becomes 0.

  • Step 1: 227 = 143 × 1 + 84
  • Step 2: 143 = 84 × 1 + 59
  • Step 3: 84 = 59 × 1 + 25
  • Step 4: 59 = 25 × 2 + 9
  • Step 5: 25 = 9 × 2 + 7
  • Step 6: 9 = 7 × 1 + 2
  • Step 7: 7 = 2 × 3 + 1
  • Step 8: 2 = 1 × 2 + 0

Since the remainder becomes 0, the last non-zero remainder is 1.

Answer: GCD(143, 227) = 1

2. Find m and n such that gcd(a, b) = ma + nb for a = 56 and b = 72

Given:

a = 56, b = 72. We need to find integers m and n such that: gcd(56, 72) = 56m + 72n.

Step 1: Find the GCD using the Euclidean Algorithm

72 = 56 × 1 + 16
56 = 16 × 3 + 8
16 = 8 × 2 + 0
Hence,... Continue reading "Number Theory Problems: GCD, Congruences, and Fermat Numbers" »

Calculating Mean and Standard Deviation in Normal Distribution

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Calculating Mean and Standard Deviation

The marks obtained in a statistics examination are normally distributed. If 15% of students scored ≥ 60 marks and 40% scored < 30 marks, find the mean (μ) and standard deviation (σ).

Given

  • P(X ≥ 60) = 0.15
  • P(X < 30) = 0.40

We need to find the values of μ and σ.


Step 1: Convert to Z-values

(i) P(X ≥ 60) = 0.15

Since P(X ≥ 60) = 0.15, then P(X < 60) = 0.85. From the standard normal table, P(Z < 1.04) = 0.85. Therefore:

(60 − μ) / σ = 1.04
μ = 60 − 1.04σ (Equation 1)


(ii) P(X < 30) = 0.40

From the standard normal table, P(Z < -0.25) = 0.40. Therefore:

(30 − μ) / σ = -0.25
μ = 30 + 0.25σ (Equation 2)


Step 3: Solve the Equations

Equating (1) and (2):

60 − 1.04σ = 30 + 0.25σ
30

... Continue reading "Calculating Mean and Standard Deviation in Normal Distribution" »

R Programming Fundamentals, SQL, and Advanced Clustering Methods

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Section A: R Basics and Data Types (Weeks 1-4)

Model Questions and Answers

Q: Create a vector v (3, NA, Inf, -Inf). Explain adding 5 to v.

A: The operation is element-wise. Missing values (NA) propagate, resulting in NA. Infinite values (Inf, -Inf) remain infinite.

v <- c(3, NA, Inf, -Inf)
print(v + 5)
# Output: [1]  8 NA Inf -Inf

Q: Given vector a, write code to count and replace NAs.

A: Assuming a <- c(10, 15, NA, 20).

  • Count NAs: sum(is.na(a)) → 1.
  • Replace NAs (e.g., with 0): a[is.na(a)] <- 0.

Q: Explain the difference between a[a > 12] and a[which(a > 12)].

A: Both select elements greater than 12 (15, 20). However:

  • a[a > 12] → [1] 15 NA (Uses logical indexing; preserves the position of NA in the original vector as NA).
  • a[which(
... Continue reading "R Programming Fundamentals, SQL, and Advanced Clustering Methods" »

Hypothesis Testing Solved Problems: Z, T, and F Tests

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Problem 9: Z-Test for Two Means

A researcher wants to know the intelligence of students in a school. He selected two groups of students. In the first group, there are 150 students having a mean IQ of 75 with a S.D. of 15. In the second group, there are 250 students having a mean IQ of 70 with a S.D. of 20. Is there a significant difference between the means of the two groups?

Solution

Given

For Group I:

  • Sample size, n1 = 150
  • Sample mean, x̄1 = 75
  • Standard deviation, s1 = 15

For Group II:

  • Sample size, n2 = 250
  • Sample mean, x̄2 = 70
  • Standard deviation, s2 = 20

Level of significance: α = 0.05

Since both sample sizes are large (n1, n2 > 30), use the Z-test for the difference between two means.

Step 1: State the Hypotheses

  • Null Hypothesis (H0): μ1 = μ2
... Continue reading "Hypothesis Testing Solved Problems: Z, T, and F Tests" »

Essential Mathematics and Statistics Formula Sheet

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Quick revision table for Mathematics and Statistics exams.

Unit I: Integration and Data Presentation

TopicFormulaUse
Integration Algebraic∫xⁿ dx = xⁿ⁺¹/(n+1) + C, n≠-1
∫1/x dx = ln|x| + C
∫k dx = kx + C
∫x dx = x²/2 + C
Finding area, antiderivative
Integration Trigonometric∫sin x dx = -cos x + C
∫cos x dx = sin x + C
∫sec²x dx = tan x + C
∫tan x dx = ln|sec x| + C
∫cot x dx = ln|sin x| + C
Trig integration
Integration Exponential∫eˣ dx = eˣ + C
∫aˣ dx = aˣ/ln a + C
Growth, decay problems
Pie Diagram AngleAngle of sector = (Component value / Total value) × 360°Constructing pie chart
Median from OgiveMedian = X-coordinate of intersection point of "less than" and "more than" ogiveGraphical method

Unit II: Central Tendency and

... Continue reading "Essential Mathematics and Statistics Formula Sheet" »

MATLAB Cheat Sheet: Functions, Operators, Loops and Plotting Syntax

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Trigonometric Functions

Trig functions (in radians): sin(x), cos(x), tan(x), acos(x), asin(x), atan(x), cosh(x), sinh(x), csc(x), sec(x), and more.

Logarithm and Exponential Functions

  • exp(x): ex
  • log(x): natural logarithm (loge(x))
  • log10(x): base-10 logarithm
  • log2(x): base-2 logarithm
  • sqrt(x): square root

Complex Numbers

  • i or j: reserved for √(-1) unless otherwise designated
  • abs(x): absolute value
  • real(x): real part of a number
  • imag(x): imaginary part of a number

Rounding Functions

  • fix(x): round towards zero
  • floor(x): round towards -∞
  • ceil(x): round towards +∞
  • round(x): round to the nearest integer

Predefined Constants

  • pi = 3.14159...
  • i, j = −1 (imaginary unit)
  • Inf = infinity

Arrays and Matrices

  • x = [1 2 3 4 5 6 7 8 9 10];: row vector with 10 columns
  • x = [1;
... Continue reading "MATLAB Cheat Sheet: Functions, Operators, Loops and Plotting Syntax" »