Simple Quantitative Displays

Key Questions

• What is meant by the skewness of a distribution?

  A normal distribution is completely symmetrical, a skew distribution is not.

  In a positively skewed distribution, the "toe" at the larger side is longer than at the other side, causing the median, and especially the mean, to move to the right. In a negatively skewed distribution these move to the left, because of a longer "toe" at the smaller values.

  While in a non-skewed normal distribution mode, median and mean are all at the same value.

  

  (pictures from internet)

  MeneerNask · 1 · Feb 11 2015
• For what kind of data would you construct a dotplot or stemplot?

  Dotplots and stemplots are suitable for the visual representation of numerical ( quantitative) data, in particular for small to medium-sized data sets .

  For categorical (qualitative) data, the bar chart is the preferable way of visual representation.

  Alex Boroda · 1 · Jun 7 2015

• This dotplot summarizes total scores for beginning golfers on a 9-hole golf course. What are the mean, median, and mode of the scores?
• What are the two major advantages of both dotplots and stemplots?
• What is a bimodal graph?
• Is a bell curve symmetric, right-skewed, or left-skewed?
• You have final exam scores from two different sections of a Chemistry course and you want to compare them. What special type of stemplot will you use for this purpose?
• For what kind of data would you construct a dotplot or stemplot?
• What is meant by the skewness of a distribution?
• How do you find five numbers which have a mean of 14 and a median of 15?
• How do you write down 5 test results that have their mean median and mode all equallying 6?
• What is the mean, median, and mode for 1,2,1,2,1,3,3,4,3?
• What is the mean, median, and mode for 3.56,4.40,6.25,1.20,8.52,1.20?
• On the day three the family was given five coupons. The value of the coupons was $12, $10, $13, $8, and $7. What is the value of the median coupon?
• Mark’s scores on his first nine assignments are: 10,10,9,9,10,8,9,10,and 8. What are the mean, median, mode, and range of his scores?
• The mean, median, and mode are all equal for this set: (3,4,5,8,x). What's the value of 'x'?
• What set of seven numbers have the same mean, median, and mode?
• Question #381b2
• If a player has scored Runs - 45,55,25,35,5,15 in No of matches 40,30,30,50,10,20 respectively, what is the median score of the player?
• If you wanted to compare the shoe sizes and the heights of all the students in your math class, what graph would you use?
• Question #d7194
• Question #5aab3