1. 2.1 Histograms and Distribution Shapes

2.  A histogram is a visual display of a frequency table  Uses bars to represent the classes  The width of the bars is the class width Histogram height→class frequency Relative frequency Histogram height→relative frequency *Comment on class boundaries p.39 p.43 #1 c and d

3. Distribution Shapes p.42 c) Skewed left or Skewed right : one tail is stretched out longer than the other. The direction of skewedness is on the side of the longer tail (the tails “tail off”/decrease) d) Bimodal : the two classes with the largest frequencies are separated by at least one class; sometimes indicates that we are sampling two populations a) Symmetrical : both the left & right sides are (roughly) the same b) Uniform or Rectangular : every class has equal frequency

4. Homework:  p. 45 #7, 8, and 11