Publications by Enid Roman
Data_605_ERoman_Discussion12
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? For this multiple regression model I ch...
5034 sym R (12787 sym/70 pcs) 3 img
Data_605_ERoman_HW11
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.) #Load the packages needed library(ggplot2) ## Warning: package 'ggplot2' was built under R version 4.2.2 library(dplyr...
9595 sym R (1906 sym/24 pcs) 6 img
ERoman_Discussion11_income_dataset.rmd
Using R, build a regression model for data that interests you. Conduct residual analysis. Was the linear model appropriate? Why or why not? For this regression model I chose the income.data file from RStudio. # Load the packages needed library(ggplot2) ## Warning: package 'ggplot2' was built under R version 4.2.2 library(dplyr) ## Warning: pack...
4201 sym R (3233 sym/23 pcs) 4 img
Data_605_ERoman_HW10
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 he bets 1 dollar each time (timid ...
1747 sym
ERoman_Respond_Discussion10
Example 11.5 Each time a certain horse runs in a three-horse race, he has probability 1/2 of winning, 1/4 of coming in second, and 1/4 of coming in third, independent of the outcome of any previous race. We have an independent trials process, but it can also be considered from the point of view of Markov chain theory. The transition matrix is ...
471 sym
Data_605_ERoman_Discussion10
Page 422 Exercise 6 In the Land of Oz example (Example 11.1), change the transition matrix by making R an absorbing state. This gives R N S R 1 0 0 N 1/2 0 1/2 S S 1/4 1/2 ...
222 sym
Data_605_ERoman_HW9
Page 363 Exercise 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 probab...
956 sym
Data 605 - ERoman_Discussion9
Page 338 Exercise 1 Let S100 be the number of heads that turn up in 100 tosses of a fair coin. Use the Central Limit Theorem to estimate P(S100 ≤ 45). n<- 100 p<- 0.5 q<-1-p mu <- n*p sigma <- sqrt(n*p*q) mu ## [1] 50 sigma ## [1] 5 pu <-(45+1/2-50)/5 print(paste0("upper bound = ", pu)) ## [1] "upper bound = -0.9" p <- pnorm(-0.9) pr...
232 sym
Data_605_ERoman_HW8
Page 303 Exercise 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? (See Exercise 10.) u=1000 n=100 x= u/n paste("The expected time for the first of these bulbs to burn out is: ",x) ## [1] "The expected time for the first of these bulb...
826 sym
Data 605 - ERoman_Discussion8
Page 289 Exercise 1 A die is rolled three times. Find the probability that the sum of the outcomes is (a) greater than 9. (b) an odd number # (A) Greater than 9 # Let's set the probability values for the sum of two die thrown as we have found above. P_S2_2 <- 1/36 P_S2_3 <- 2/36 P_S2_4 <- 3/36 P_S2_5 <- 4/36 P_S2_6 <- 5/36 P_S2_7 <- 6/36 ...
148 sym Python (1920 sym/4 pcs)