In 1898, Hermon Bumpus collected house sparrows that had been caught in a severe winter storm in Chicago. He made several measurements on these sparrows, and his data are in the file " ". Bumpus used these data to observe differences between the birds that survived and those that died from the storm. This became one of the first direct and quantitative observations of natural selection on morphological traits. Here, let's use these data to practice looking for fit of the normal distribution. (We'll return to this data set next week to look for evidence of natural selection.)
a. Use ggplot() to plot the distribution of total length (this is the length of the bird from beak to tail). Does the data look as though it comes from distribution that is approximately normal?
b. Use qqnorm() to plot a QQ plot for total length. Does the data fall approximately along a straight line in the QQ plot? If so, what does this imply about the fit of these data to a normal distribution?
c. Calculate the mean of total length and a 95% confidence interval for this mean. War refer back to Week 4 for the R cor Is to do this )