library(tidyverse)
## -- Attaching packages ----------------- tidyverse 1.3.0 --
## v ggplot2 3.3.2     v purrr   0.3.4
## v tibble  3.0.3     v dplyr   1.0.2
## v tidyr   1.1.2     v stringr 1.4.0
## v readr   1.3.1     v forcats 0.5.0
## -- Conflicts -------------------- tidyverse_conflicts() --
## x dplyr::filter() masks stats::filter()
## x dplyr::lag()    masks stats::lag()

Place count of nerve cells in a vector

ncells<- c(35,19,33,34,17,26,16,40, 28,30,23,12,27,33,22,31,28,28,35,23,23,19,29)
str(ncells)
##  num [1:23] 35 19 33 34 17 26 16 40 28 30 ...
id <- c(1:23)

compute median, quartiles 1 and 3, and IQR which will be median = 28, Q1 = 22.5, Q2 = 32, IQR = 9.5

median(ncells)
## [1] 28
q1 <- quantile(ncells, prob = .25)
q1
##  25% 
## 22.5
q3 <- quantile(ncells, prob = .75)
q3
## 75% 
##  32
#compute q3 - q1 for IQR
IQR <- q3 -  q1
IQR
## 75% 
## 9.5

Create a boxplot for data

boxplot(ncells)