Publications by Maryluz Cruz
hw9
11. The price of one share of stock in the Pilsdorff Beer Company (see Exercise 8.2.12) is given by Yn on the nth day of the year. Finn observes that the differences Xn = Yn+1 − Yn appear to be independent random variables with a common distribution having mean µ = 0 and variance σ 2 = 1/4. If Y1 = 100, estimate the probability that Y365 is ...
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Homework 8
11. 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? 1000/100 ## [1] 10 14. Assume that X1 and X2 are independent random variables, each having an exponential density with parameter λ. Show that Z = X1 − X2 has density \[\begin{equation}...
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discussion 8
1. A die is rolled three times. Find the probability that the sum of the outcomes is greater than 9. 36 ways for a dice. One way to roll A 12 which is 6+6 , then thees 2 ways for 11 which is 5 + 6 and 6 + 5, and then there are 3 ways to get 10. Therefore P(>9) = P(10) + P(11) + P(12) = 3/36 + 2/36 + 1/36 = 1/6 But since we are rolling the dice...
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Data 607 Final Presentation
12/12/2019 Social Media and Adolescents and affects of Mental Health Sentiment Analysis Presentation Motivation The motivation behind this assignment is that I have a niece that is in her pre-teens sometimes I wonder if she got into Social Media too early. Based on these articles it seems like Social Media is not exactly a good thing for someon...
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Data 607 Final Project
Data 607 Final Project Introduction and Motivation For this assignment I will be scraping data from three different web articles that discuss how Social Media affects Adolescents and Children and how it affects there mental health. For this assignment I will do a text analysis of the scraped data and do a sentiment analysis based on the scraped...
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Tidyverse Assignment Part 1
Load the Tidyverse Package require(tidyverse) ## Loading required package: tidyverse ## -- Attaching packages ------------------------------------------------------------------------------- tidyverse 1.3.0 -- ## v ggplot2 3.2.1 v purrr 0.3.3 ## v tibble 2.1.3 v dplyr 0.8.3 ## v tidyr 1.0.0 v stringr 1.4.0 ## v readr 1.3.1 ...
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Tidyverse Assignment Part 2 - Extended Project
Part 1 Original Tidyverse Assignment By Amber Ferger The Data: What Do Men Think It Means to be a Man? For this assignment, I decided to use the dataset that corresponds to the What Do Men Think It Means To Be A Man? article on FiveThirtyEight.com. The article can be found here: https://fivethirtyeight.com/features/what-do-men-think-it-means-to-...
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data606Project
Part 1 - Introduction Question: What day of the week do parents prefer to give birth? In an article that I read from fivethirtyeight, they were discussing that there are parents that don’t want to have kids on a Friday fearing that it would fall on Friday the 13th. It makes one wonder are people really that superstitious. Would it really be ba...
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Data 605 HW 1
ASSIGNMENT 1 Data 605 1. Problem set 1 (1) Calculate the dot product u.v where u = [0.5; 0.5] and v = [3; −4] u <- c(.5,.5) v <- c(3, -4) dotuv <- u %*% v dotuv ## [,1] ## [1,] -0.5 (2) What are the lengths of u and v? Please note that the mathematical notion of the length of a vector is not the same as a computer science definiti...
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Data 605 Discussion 6
Chapter 3.2 questions 2 and 3 page 113 2. In how many ways can we choose five people from a group of ten to form a commitee? \[p=\frac{a!}{b!(a-b)!}\] \[p=\frac{10!}{5!(10-5)!}\] \[p=\frac{3628800}{120 *5!}\] \[p=\frac{3628800}{120 *5!}\] \[p=\frac{3628800}{14400}\] \[p=252\] Now lets test this in R using the choose function: choose(10,5) ## [1]...
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