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Finding the Fourth Proportional to 653.60, 978.80 and 490.40

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Solution

The fourth proportional to 653.60, 978.80 and 490.40 is: 734.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    653.60 : 978.80 = 490.40 : x
  2. Step 2: Convert to fraction form
    653.60/978.80 = 490.40/x
  3. Step 3: Cross multiply
    653.60x = 978.80 × 490.40
  4. Step 4: Simplify right side
    653.60x = 480,003.52
  5. Step 5: Solve for x
    x = 480,003.52/653.60
  6. Step 6: Final answer
    x = 734.40

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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.