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Finding the Fourth Proportional to 404.80, 558.72 and 306.40

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Solution

The fourth proportional to 404.80, 558.72 and 306.40 is: 422.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    404.80 : 558.72 = 306.40 : x
  2. Step 2: Convert to fraction form
    404.80/558.72 = 306.40/x
  3. Step 3: Cross multiply
    404.80x = 558.72 × 306.40
  4. Step 4: Simplify right side
    404.80x = 171,191.81
  5. Step 5: Solve for x
    x = 171,191.81/404.80
  6. Step 6: Final answer
    x = 422.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.