Unit 2 Special centers; Trimmed & Weighted Mean
Let’s look at some data How Fast Food Compare Company Fast FoodTotalFatCholesterolSodium Calories(g)(mg) Kentucky Fried Chicken Lite 'n Crispy (4 pieces) Burger King Hamburger Deluxe Wendy's Single (plain) Kentucky Fried Chicken Original Recipe (4pieces) McDonald's Chicken McNuggets (6) Arby's Regular Roast Beef Kentucky Fried Chicken Extra Crispy (4 pieces) McDonald's Quarter Pounder McDonald's McLean Deluxe Arby's French Dip Wendy's Chicken (regular) Hardee's Big Deluxe Burger Burger King BK Broiler Chicken McDonald's McChicken Comparing various fast food components of nutrition. Calories Fat Cholesterol Sodium
The Mean grams of Fat in the fast foods Fat (g)
The Trimmed Mean Fat (g) Do you notice that one particular value is possibly an outlier. In order to better compute a “truer” average we will use a “Trimmed” mean.
The Trimmed Mean The trimmed mean has the advantage of being relatively resistant to outliers. The trimmed mean is computed just as an ordinary mean...except. a pre-specified percentage of the extremes is omitted. Consider the 5% trimmed mean. The left-most (lowest) 5% and right-most (highest) 5% of the data are excluded; from the remaining observations the mean is found. So, the 10% most "extreme" data (5% on either side) is omitted before computing the mean.
Trimmed Mean Fat (g) % Trim Drop the 2 smallest & 2 largest values
The Trimmed Mean Fat (g)
The Trimmed Mean – you try it Fat (g)
The Weighted Mean weighted mean The weighted mean is used when the values in a data set are not all equally represented. weighted meanof a variable X The weighted mean of a variable X is found by multiplying each value by its corresponding weight and dividing the sum of the products by the sum of the weights.
The Weighted Mean
Cost of Shoes ($) ShoeCost No. Sold Air Jordan$1403 KD$1354 Kobe$2001 Air Force$855 Converse$459
The Weighted Mean- using the table Cost of Shoes ($) Shoe Cost (x) No. Sold ( w ) wxwx Air Jordan$1403$420 KD$1354$540 Kobe$2001 Air Force$855$425 Converse$459$405 totals22$ 1990