STAT 1000Q Lecture Notes - Lecture 3: Central Tendency, 1, 2 Step, Negative Number

• School: UConn
• Department: Statistics
• Course: STAT 1000Q
• Professor: Zhanna Pozdnyakova

Document Summary

Central point: sample mean (arithmetic average, the most popular and useful measure of central location, x = (cid:3117)+(cid:3118)+ , where x"s = data points and n = sample size, example 1. Step 2: sort data from smallest to largest. = 0: if n is odd, if n is even, +(cid:2869)(cid:2870, (cid:3118),(cid:3118)+(cid:2869)(cid:2870, example 2. Relationship among mean and median: in the case of bell-shaped distribution, Lecture 3: in the case of positively skewed distribution, Mean > median: in the case of negatively skewed distribution, Mode: the data point that appears most frequently. Mean < median: range, largest observation smallest observation, example. 10, -8, -6, -5, -1, 0, 2, 4, 5, 6, 8, 10. Range = 10 (-10) = 20: takes into account only smallest and largest observations, sample variance and sample standard deviation. Lecture 3: where all x"s are data points and n is sample size, sample variance = (cid:2870, (cid:2870)= (cid:4666)(cid:3117) x (cid:4667)(cid:3118)+(cid:4666)(cid:3118) x (cid:4667)(cid:3118) .