# Samples and Populations

## Presentation on theme: "Samples and Populations"— Presentation transcript:

Samples and Populations
Investigation 1 Comparing Data Sets

Brand Name VS. Generic

What is your preference in colas?
Brand Name VS. Store Name

Mathematical and Problem-Solving Goals
To engage in the process of statistical investigation. To compare data using tables, stem-and-leaf plots, histograms, and box-and-whiskers plots. To compare data using measures of center (mean and median) and measures of spread (range). To consider the properties of the mean and median, particularly the influence of extreme values on each measure’s calculation.

Think about this……. Who might be interested in the result of this peanut butter study? What interesting questions about peanut butter can be answered with these data? What interesting question cannot be answered with these data?

Problem 1.1 Apply some of the data techniques you learned in earlier statistics work to compare the quality ratings for natural brands and regular brands. In general, do natural or regular brands have higher quality ratings? Use the results of your analysis to justify your choice.

Problem 1.1 Follow - Up 1. For the quality ratings of the regular brands, the mean is greater than the median. Why do you thing this is true? 2. For the quality ratings of the natural brands, the mean and the median are close in value. Why do you think this is true?

1.2 Using Box-and-Whisker Plots
Box-and-Whisker plots, or box plots, are useful representations of the distribution of values in a data set. The box plot below shows the distribution of quality ratings for the natural brands of peanut butter.