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Finding the Fourth Proportional to 309.60, 464.40 and 259.20

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Solution

The fourth proportional to 309.60, 464.40 and 259.20 is: 388.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.60 : 464.40 = 259.20 : x
  2. Step 2: Convert to fraction form
    309.60/464.40 = 259.20/x
  3. Step 3: Cross multiply
    309.60x = 464.40 × 259.20
  4. Step 4: Simplify right side
    309.60x = 120,372.48
  5. Step 5: Solve for x
    x = 120,372.48/309.60
  6. Step 6: Final answer
    x = 388.80

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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.