Publications by Jimmy Ng
data 605: HW7 model machine lifetime failure after 8 years in use
Code Show All Code Hide All Code data_605_hw7 data_605_hw7 Question 1 Question 2 Jimmy Ng 10/7/2021 Question 1 Let X1, X2, . . . , Xn be n mutually independent random variables, each of which is uniformly distributed on the integers from 1 to k. Let Y denote the minimum of the Xi’s. Find the distribution of Y. Answer: The goal is to fi...
2848 sym R (3796 sym/24 pcs)
data 605: Chebyshev’s Inequality
Code Show All Code Hide All Code data_605_hw8 data_605_hw8 Problem 11 (p. 303) Problem 14 (p. 303) Problem 1 (p. 320 - 321) Jimmy Ng 10/12/2021 Problem 11 (p. 303) A company buys 100 lightbulbs, each of which has an exponential lifetime of 1000 hours. What is the expected time for the first of these bulbs to burn out? (See Exercise 1...
1161 sym R (443 sym/3 pcs)
data 605: discussion 12
Discussion 12 Using R, build a multiple regression model for data that interests you. Include in this model at least one quadratic term, one dichotomous term, and one dichotomous vs. quantitative interaction term. Interpret all coefficients. Conduct residual analysis. Was the linear model appropriate? Why or why not? Set up This is a simple dat...
1612 sym R (4612 sym/28 pcs) 3 img
data 605: discussion 13
Discussion 13 Section 4.2: Exercise 9 A 24 ft. ladder is leaning against a house while the base is pulled away at a constant rate of 1 ft/s. At what rate is the top of the ladder sliding down the side of the house when the base is at various distances from the house: I solved this problem entirely based on this excellent video from Professor Dave...
1239 sym R (960 sym/2 pcs)
data 605: calculus
Code Show All Code Hide All Code data_605_hw13 data_605_hw13 Q1 Q2 Q3 Q4 Q5 Q6 Q7 Jimmy Ng 11/19/2021 Q1 Use integration by substitution to solve the integral below. \[\int_{}^{} 4e^{-7x}dx\] \[u = -7x\] \[\frac{du}{dx} = -7\] \[du = -7dx\] \[dx = \frac{du}{-7}\] \[\int_{}^{} 4e^{u}\frac{du}{-7}\] \[-\frac{4}{7}\int_{}^{}e^udu\] \[= -\fr...
3765 sym R (255 sym/3 pcs) 1 img
data 698: final project
Code Show All Code Hide All Code data_698_presentation data_698_presentation (0) configuration set-up (1) step 1: data extraction extraction (2) step 2: data transformation: indicator, risk transformation (3) step 3: data transformation: strategy technical analysis wrangling (4) step 4: ML - random forest ...
1666 sym R (12796 sym/36 pcs) 4 img 31 tbl