Question

2. Vocabulary and R functions

a) What does the symbol x-bar represent?

b) What does the Greek letter mu (μ) represent?

c) What is the difference between x-bar and mu?

3. Mean

a) 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. In your own words, another method of finding the mean by using the sample space (list of possible values) and probabilities. 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.

b) Describe in your own words what your calculation is doing and what the answer means.

Answer 1

2. Vocabulary and R functions

a) What does the symbol x-bar represent?

Answer) x- bar represents the sample mean

b) What does the Greek letter mu (μ) represent?

Answer) Greek letter mu represents the population mean

c) What is the difference between x-bar and mu?

Answer) The sample mean is a “statistic”; the population mean a “parameter”. We use statistics to estimate parameters and conduct hypothesis tests about the values of unknown parameters of interest.