# bowl: A sampling bowl of red and white balls In moderndive: Tidyverse-Friendly Introductory Linear Regression

## Description

A sampling bowl used as the population in a simulated sampling exercise. Also known as the urn sampling framework https://en.wikipedia.org/wiki/Urn_problem.

## Usage

 `1` ```bowl ```

## Format

A data frame 2400 rows representing different balls in the bowl, of which 900 are red and 1500 are white.

ball_ID

ID variable used to denote all balls. Note this value is not marked on the balls themselves

color

color of ball: red or white

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22``` ```library(dplyr) library(ggplot2) # Take 10 different samples of size n = 50 balls from bowl bowl_samples_simulated <- bowl %>% rep_sample_n(50, reps = 10) # Compute 10 different p_hats (prop red) based on 10 different samples of # size n = 50 p_hats <- bowl_samples_simulated %>% group_by(replicate, color) %>% summarize(count = n()) %>% mutate(proportion = count / 50) %>% filter(color == "red") # Plot sampling distribution ggplot(p_hats, aes(x = proportion)) + geom_histogram(binwidth = 0.05) + labs( x = expression(hat(p)), y = "Number of samples", title = "Sampling distribution of p_hat based 10 samples of size n = 50" ) ```

moderndive documentation built on Jan. 9, 2021, 1:34 a.m.