If David were summarizing the data from his sample, he would use statistics. If he wanted to know whether or not his sample results could be generalized to the population, he would use statistics.

If David were summarizing the data from his sample, he would use Descriptive statistics. If he wanted to know whether or not his sample results could be generalized to the population, he would use Hypothesis testing statistics.

Step-by-step explanation:

Hello!

There are two types of statistics.

1. Descriptive statistics.

This method allows you to summarize the observed data of a sample, it gives you an idea of the data distribution shape, its variability, most common values, etc... You can summarize the data using numerical measures (for example: mean, median, mode, variance) or graphics (for example histogram, scatterplots, boxplots)

2. Hypothesis testing.

Using this method you can test the results of an experiment, using the previously summarized sample data, and reach a valid conclusion over your claims that can be generalized to the population of study afterward.

I hope it helps!

$5.41

step-by-step explanation:

$20 - $14.51 = $5.49.