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Finding the Fourth Proportional to 652.60, 978.90 and 287.20

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Solution

The fourth proportional to 652.60, 978.90 and 287.20 is: 430.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    652.60 : 978.90 = 287.20 : x
  2. Step 2: Convert to fraction form
    652.60/978.90 = 287.20/x
  3. Step 3: Cross multiply
    652.60x = 978.90 × 287.20
  4. Step 4: Simplify right side
    652.60x = 281,140.08
  5. Step 5: Solve for x
    x = 281,140.08/652.60
  6. Step 6: Final answer
    x = 430.80

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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.