. \\ '51,..-\"un. .7, MATH 1280 Learning Journal Unit 4 2. Vocabulary and R functions a) What does the symbol x-bar represent? . . b) What does the Greek letter mu (u) represent as It was used in this week's lessons? 0) What is the difference between xbar and mu? 3. Mean 0) Many people already know how to find the mean (average) of a sample of data by "adding all the numbers and dividing by the number of values in the dataset." Read Chapter 4, and then ' describe, in your own words, another method of finding the mean by using the sample space (list of possible values) and probabilities (the\\technique is in the book). Create a list of seven, 2-digit numbers (with no duplicates) and another set of seven probabilities (with no duplicates). The probabilities must add to 1. Open R, and manually enter those numbers and their corresponding probabilities to calculate the mean using only addition and multiplication (in other words, enter only the numbers, the plus sign, and the * for multiplication, like on the bottom of Yakir, 2011, p. 57). Paste all the R output into your learning journal. b) Describe in your own words what your calculation is doing and what the answer means. Q .I / / \\