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Finding the Fourth Proportional to 870.72, 1,306.62 and 323.28

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Solution

The fourth proportional to 870.72, 1,306.62 and 323.28 is: 485.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.72 : 1,306.62 = 323.28 : x
  2. Step 2: Convert to fraction form
    870.72/1,306.62 = 323.28/x
  3. Step 3: Cross multiply
    870.72x = 1,306.62 × 323.28
  4. Step 4: Simplify right side
    870.72x = 422,404.11
  5. Step 5: Solve for x
    x = 422,404.11/870.72
  6. Step 6: Final answer
    x = 485.12

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.