Publications by Kristin Lussi

DATA 605 Homework 14

04.05.2024

Week 14 Homework This week, we’ll work out some Taylor Series expansions of popular functions. \(f(x) = \frac{1}{(1-x)}\) \(f(x) = e^x\) \(f(x) = ln(1+x)\) \(f(x) = x^{(1/2)}\) For each function, only consider its valid ranges as indicated in the notes when you are computing the Taylor Series expansion. To calculate the expansions, we will use ...

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DATA 605 Week 14 Discussion

02.05.2024

Page 496 Exercise 27 Use the Taylor series given in Key Idea 8.8.1 to create the Taylor series of the given functions. \(f(x)=sin(2x+3)\) Solution using R library(pracma) f <- function(x) sin(2*x + 3) taylor_series <- taylor(f, 0) print(taylor_series) ## [1] 0.09407953 1.31998927 -0.28224001 -1.97998499 0.14112001 Solution by Hand Calcula...

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DATA 605 Homework 13

20.04.2024

Homework 13 Question 1 Use integration by substitution to solve the integral below. \[ \int 4e^{-7x}dx \] Solution \[ u = -7x \\ du = -7 dx \rightarrow \frac{-1}{7}du = dx\\ \int 4e^{-7x}dx \rightarrow \text{ Substitute } \rightarrow 4 \int e^u \frac{-1}{7} du\\ = \frac{-4}{7} \int e^u du = \frac{-4}{7} e^u + C \\ = \frac{-4}{7} e^{-7x} + C \] Q...

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DATA 605 Week 13 Discussion

18.04.2024

Page 395 #5 A 100 ft rope, weighing 0.1 lb/ft, hangs over the edge of a tall building. Part A Question How much work is done pulling the entire rope to the top of the building? Solution \[ 0 \leq x \leq 100\\ dW = \text{amount of work required to lift a segment of the rope a distance x from its current position} =0.1 x dx\\ x = \text{height}\\ ...

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DATA 605 Homework 12

15.04.2024

Import Data who_data <- read_csv(url, show_col_types = FALSE) head(who_data) ## # A tibble: 6 × 10 ## Country LifeExp InfantSurvival Under5Survival TBFree PropMD PropRN PersExp ## <chr> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> ## 1 Afghanis… 42 0.835 0.743 0.998 2.29e-4 5.72e-4 ...

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DATA 605 Discussion Week 12

12.04.2024

Medical Expenses In this analysis, I will be using the Insurance Premium Prediction dataset from Kaggle. I will determine which variables in the dataset are significant predictors of medical expenses by creating a multiple linear regression model. Import Data url <- "https://raw.githubusercontent.com/kristinlussi/DATA605/main/Week12/insurance.csv"...

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DATA 605 Homework 11

07.04.2024

Cars Analysis Using the “cars” dataset in R, build a linear model for stopping distance as a function of speed and replicate the analysis of your textbook chapter 3 (visualization, quality evaluation of the model, and residual analysis.) library(dplyr) library(ggplot2) data(cars) Let’s take a glimpse of the data. head(cars) ## speed dist ##...

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DATA 605 Week 11 Discussion

04.04.2024

Introduction The dataset I will be working with is the Housing Prices Dataset from Kaggle. I will be creating a linear model that explains the relationship between area and housing price. Visualize the Data houses <- read.csv("https://raw.githubusercontent.com/kristinlussi/DATA605/main/WEEK11/Housing.csv") head(houses) ## price area bedrooms ...

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DATA 605 Homework 10

30.03.2024

Question Smith is in jail and has 1 dollar; he can get out on bail if he has 8 dollars. A guard agrees to make a series of bets with him. If Smith bets A dollars, he wins A dollars with probability .4 and loses A dollars with probability .6. Find the probability that he wins 8 dollars before losing all of his money if a. he bets 1 dollar each time...

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DATA 605 Week 10 Discussion

28.03.2024

Page 445 #28 Prove that P and (1/2)(I + P) have the same fixed vectors. Solution First we will show that \(\frac{1}{2}(I+P)x=x\) implies \(Px=x\). Expanding the formula: \(\frac{1}{2}(I+P)x \rightarrow \frac{1}{2}Ix + \frac{1}{2}Px =x\) As per the definition of the identity matrix, \(Ix=x\), so we can simplify to: \[ \frac{1}{2}x +\frac{1}{2} Px =...

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