Need help getting my boxplot produce in rstudio with this data set:

https://docs.google.com/spreadsheets/d/1iLDRc18sHMO5-rcY7S4Z_h2aUk7CPoieaMwPSwVdpJc/edit?usp=sharing

Prompt:

Make boxplots of your new variable, WACTtoJINS by school of respondent (Q27)

ggplot(data=Facwriting)+geom_boxplot(mapping=aes(x=School, y=WACTtoJINS))

error:

Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous. Error: Aesthetics must be either length 1 or the same as the data (90): x, y

Here is some code that I have:

library(readr) Facwriting <- read_csv("~/stat 220/hw2/hw2/Facwriting.csv")

WACTtoJINS<-mutate(Facwriting,WACTtoJINS=round(as.numeric(Facwriting$WACTimprove) /as.numeric(Facwriting$JINSImprove),digits = 3))

Is ther any way to fix this "aesthetics" error please?