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Finding the Fourth Proportional to 478.40, 660 and 347.12

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Solution

The fourth proportional to 478.40, 660 and 347.12 is: 478.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.40 : 660 = 347.12 : x
  2. Step 2: Convert to fraction form
    478.40/660 = 347.12/x
  3. Step 3: Cross multiply
    478.40x = 660 × 347.12
  4. Step 4: Simplify right side
    478.40x = 229,099.20
  5. Step 5: Solve for x
    x = 229,099.20/478.40
  6. Step 6: Final answer
    x = 478.89

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.