Business statistics

Chapter 3. Descriptive Statistics: Numerical Measures

3.1. Measures of Location

Mean

• In the preceding formula, the numerator is the sum of the values of the n observations. That is,
• The Greek letter ∑ (sigma) is the summation sign. To illustrate the computation of a sample mean, let us consider the following class size data for a sample of five college classes.

46 54 42 46 32

Chapter 3. Descriptive Statistics: Numerical Measures

3.1. Measures of Location

Mean

• We use the notation X1, X2, X3, X4, X5 to represent the number of students in each of the five classes.
• X1 = 46 X2 = 54 X3 = 42 X4 = 46 X5 = 32
• Hence, to compute the sample mean, we can write
• The sample mean class size is 44 students.

Chapter 3. Descriptive Statistics: Numerical Measures