In this chapter, we will look at some charts and graphs used to summarize quantitative data. We will also look at numerical analysis of such data.

A way of listing all data values in a condensed format:  while not required, it helps to have the data sorted  choose the digit to be the stem (10’s place, 100’s place…)  put the stems in increasing (or decreasing) order in a column  next to each stem, put leaves in increasing order, left to right

Construct a stem and leaf display for wingspans in “ACSC” using the 10’s digit as the stem.

Sometimes, if the data are clumped together in a small range of values, we use repeated stems – that is, each stem is listed twice  next to the first copy of the stem, all leaves from the lower half of the possible leaf values are listed  next to the second copy of the stem, all leaves from the upper half of the possible leaf values are listed

Construct a stem and leaf display for wingspans in “ACSC” using the 10’s digit as the stem and using repeated stems.

The quantitative data equivalent of a bar chart:

Construct a histogram for wingspans in “ACSC” with bins 10 wide.

Construct a histogram for wingspans in “ACSC” with bins 5 wide.

This histogram is skewed to the left.

 The median of a data set is the middle value of the ordered set  If n is odd, the median is the value that cuts the list in half  If n is even, the median is the average of the two middle values

Find the median of the given data sets. The first is the heights of females in “ACSC” while the second is the heights of females with brown hair in “ACSC”. (a) (b)

Find the range and interquartile range of the heights of females in “ACSC”

5-Number Summary via TI 83/84 press and then enter the data in L1 press to select 1-Var Stats press to perform the command, then scroll down to see results

 The sample mean of a data set is the average of the values   the population mean is denoted 

Find the mean, variance, standard deviation, and the 5-number summary of wingspans from the data in “ACSC”.