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Finding the Fourth Proportional to 486.60, 728.50 and 312.80

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Solution

The fourth proportional to 486.60, 728.50 and 312.80 is: 468.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.60 : 728.50 = 312.80 : x
  2. Step 2: Convert to fraction form
    486.60/728.50 = 312.80/x
  3. Step 3: Cross multiply
    486.60x = 728.50 × 312.80
  4. Step 4: Simplify right side
    486.60x = 227,874.80
  5. Step 5: Solve for x
    x = 227,874.80/486.60
  6. Step 6: Final answer
    x = 468.30

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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.