# Gestation classroom exercise

16 Jun 2015

#Objective We are learning about univariate descriptive plots and statistics: the histogram, box-and-whisker plot, mean, pecentiles, standard deviation. Additionally, we emphasize that plotting is the first step to understanding your data. The distinction between descriptive/inferential statistics is something we’ve talked about - the last question is supposed to inspire some critical thinking.

#Setup I sampled 80 babies from the “Birth Weight II” data set at Deborah Nolan and Terry Speed’s Stat Labs website. For each baby, I wrote its gestation length (in days) on a cheap white poker chip. The chips were placed in one communal basket at the head of the class - each team sent a sampler and a recorder up to draw their sample. I assigned different sample sizes to each group (11, 15, or 19, to make quartiles easy).

#Exercise

Your group has been assigned a sample size. From the central urn, draw your sample with replacement:

1. Grab one chip from the urn
2. Note the gestation length written on the chip and add it to your list.
3. Return the chip the the urn and repeat.

## Calculate summary statistics

Calculate the min, max, mean, median, first and third quartile, IQR, and standard deviation.

## Plot the data

Based on your sample, make a box-and-whisker plot of gestation period. Annotate it with the statistics you calculated in the previous step. How many of the samples were within one standard deviation of the mean?