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Finding the Fourth Proportional to 478.45, 717.80 and 386.74

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Solution

The fourth proportional to 478.45, 717.80 and 386.74 is: 580.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.45 : 717.80 = 386.74 : x
  2. Step 2: Convert to fraction form
    478.45/717.80 = 386.74/x
  3. Step 3: Cross multiply
    478.45x = 717.80 × 386.74
  4. Step 4: Simplify right side
    478.45x = 277,599.07
  5. Step 5: Solve for x
    x = 277,599.07/478.45
  6. Step 6: Final answer
    x = 580.20

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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.