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Sample Size from Histogram

Sep 3, 2025

Overview

This lecture explains how to determine the sample size from a histogram summarizing the amount of sugar in organic snacks.

Interpreting the Histogram

  • The horizontal axis represents intervals of sugar amounts (in milligrams) for each snack.
  • The vertical axis shows the frequency, or the number of snacks, in each sugar interval.
  • The height of each histogram bar corresponds to the frequency for that interval.

Calculating Sample Size

  • Frequency for the first interval: 4 snacks.
  • Frequency for the second interval: 4 snacks.
  • Frequency for the third interval: 9 snacks.
  • Frequency for the fourth interval: 14 snacks.
  • Frequency for the fifth interval: 10 snacks.
  • Frequency for the sixth interval: 3 snacks.
  • Frequency for the seventh interval: 3 snacks.
  • Total sample size (n) = 4 + 4 + 9 + 14 + 10 + 3 + 3 = 47 snacks.

Key Terms & Definitions

  • Histogram — a bar graph representing the frequency of data within specified intervals.
  • Frequency — the number of observations within a particular interval.
  • Sample Size (n) — the total number of observations in the data set.

Action Items / Next Steps

  • Practice calculating sample size using histograms with different data sets.