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Finding the Fourth Proportional to 459.78, 690.88 and 429.80

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Solution

The fourth proportional to 459.78, 690.88 and 429.80 is: 645.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    459.78 : 690.88 = 429.80 : x
  2. Step 2: Convert to fraction form
    459.78/690.88 = 429.80/x
  3. Step 3: Cross multiply
    459.78x = 690.88 × 429.80
  4. Step 4: Simplify right side
    459.78x = 296,940.22
  5. Step 5: Solve for x
    x = 296,940.22/459.78
  6. Step 6: Final answer
    x = 645.83

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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.