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Finding the Fourth Proportional to 829.80, 1,245.72 and 459.90

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Solution

The fourth proportional to 829.80, 1,245.72 and 459.90 is: 690.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    829.80 : 1,245.72 = 459.90 : x
  2. Step 2: Convert to fraction form
    829.80/1,245.72 = 459.90/x
  3. Step 3: Cross multiply
    829.80x = 1,245.72 × 459.90
  4. Step 4: Simplify right side
    829.80x = 572,906.63
  5. Step 5: Solve for x
    x = 572,906.63/829.80
  6. Step 6: Final answer
    x = 690.42

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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.