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Finding the Fourth Proportional to 478.72, 660.65 and 282.40

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Solution

The fourth proportional to 478.72, 660.65 and 282.40 is: 389.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.72 : 660.65 = 282.40 : x
  2. Step 2: Convert to fraction form
    478.72/660.65 = 282.40/x
  3. Step 3: Cross multiply
    478.72x = 660.65 × 282.40
  4. Step 4: Simplify right side
    478.72x = 186,567.56
  5. Step 5: Solve for x
    x = 186,567.56/478.72
  6. Step 6: Final answer
    x = 389.72

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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.