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Finding the Fourth Proportional to 478.79, 660.31 and 385.50

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Solution

The fourth proportional to 478.79, 660.31 and 385.50 is: 531.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.79 : 660.31 = 385.50 : x
  2. Step 2: Convert to fraction form
    478.79/660.31 = 385.50/x
  3. Step 3: Cross multiply
    478.79x = 660.31 × 385.50
  4. Step 4: Simplify right side
    478.79x = 254,549.09
  5. Step 5: Solve for x
    x = 254,549.09/478.79
  6. Step 6: Final answer
    x = 531.66

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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.