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13.1: Error de muestreo (Sección @ref {samplingerror})

  • Page ID
    150697
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    Aquí vamos a muestrear repetidamente de la variable Altura NHANES para obtener la distribución muestral de la media.

    sampSize <- 50 # size of sample
    nsamps <- 5000 # number of samples we will take
    
    # set up variable to store all of the results
    sampMeans <- tibble(meanHeight=rep(NA,nsamps))
    
    # Loop through and repeatedly sample and compute the mean
    for (i in 1:nsamps) {
      sampMeans$meanHeight[i] <- NHANES_adult %>%
        sample_n(sampSize) %>%
        summarize(meanHeight=mean(Height)) %>%
        pull(meanHeight)
    }

    Ahora vamos a trazar la distribución de muestreo. También se sobrepondremos la distribución muestral de la media predicha sobre la base de la media poblacional y la desviación estándar, para mostrar que describe adecuadamente la distribución muestral real.

    # pipe the sampMeans data frame into ggplot
    sampMeans %>% 
      ggplot(aes(meanHeight)) +
      # create histogram using density rather than count
      geom_histogram(
        aes(y = ..density..),
        bins = 50,
        col = "gray", 
        fill = "gray"
      ) +
      # add a vertical line for the population mean
      geom_vline(xintercept = mean(NHANES_adult$Height),
                 size=1.5) +
      # add a label for the line
      annotate(
        "text",
        x = 169.6, 
        y = .4,
        label = "Population mean",
        size=6
      ) +
      # label the x axis
      labs(x = "Height (inches)") +
      # add normal based on population mean/sd
      stat_function(
          fun = dnorm, n = sampSize,
          args = list(
            mean = mean(NHANES_adult$Height),
            sd = sd(NHANES_adult$Height)/sqrt(sampSize)
          ), 
          size = 1.5,
          color = "black",
          linetype='dotted'
        ) 


    This page titled 13.1: Error de muestreo (Sección @ref {samplingerror}) is shared under a not declared license and was authored, remixed, and/or curated by Russell A. Poldrack via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.