Answer:
The population mean (μ) = 26.
Step-by-step explanation:
a) Data and Calculations:
The population characteristics = 20 and 36
Total population of interest = 56 (20 + 36)
Number of groups in the population = 2
Therefore, the population mean (μ) = 56/2 = 28
b) Based on the parameters given in this example, the population mean equals the average of the group characteristic (attention span of individuals in minutes) or item of interest. The population mean is calculated by adding the values of the group characteristic and then dividing the result by the number of values.