Fix legend, closes #251

Author: mine-cetinkaya-rundel

exercises/05-ex-explore-numerical.Rmd

@@ -486,7 +486,7 @@ Also shown below is a spatial intensity map of the same data.^[The [`county_comp
 
     p_map <- ggplot(map_county, aes(x = long, y = lat, group = group)) +
       geom_polygon(aes(fill = mean_work_travel_2017)) +
-      scale_fill_viridis_c(option = "D", labels = label_percent(scale = 1)) +
+      scale_fill_viridis_c(option = "D") +
       labs(x = NULL, y = NULL, fill = "Mean\ntravel time\n(in min)") +
       theme(
         axis.text = element_blank(),