HW1 solutions: 

3.1 b. Make sure that the bars do not touch one another.

3.4 Note that the last two class intervals should be 0.955-1.005 and
  1.005-1.055.  
 
    Make sure that the bars in a histogram touch one another. 

Problem 3. Stem-and-leaf plot for the data in Ex. 3.6: 

Stem unit = 0.1 (or Leaf Unit = 0.01)

  7 | 2
  7 | 5 6 7 8 9 
  8 | 1 2 3 3 4 4
  8 | 5 5 6 8 9 9 
  9 | 2 3 4 4
  9 | 7 7 
 10 | 
 10 | 5

(It is OK if the numbers in each row to the right of the vertical line 
are not ordered.)

3.31 a. Luxury: ybar=145.0, s=27.6
        Budget: ybar=46.1, s=5.13
     b. 27.6>5.13
     c. Luxury hotels vary in quality, location and price, whereas budget 
        hotels are more competitive for the low-end market so prices tend 
        to be similar.

3.34 b. The distribution is approximately symmetric. 

Problem 5. min=250, max=386, median=(315+320)/2=317.5
           Q1=(295+301)/2=298, Q3=(334+334)/2=334
   Thus, range=386-250=136 and IQR=Q3-Q1=334-298=36