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Finding the Fourth Proportional to 785.20, 1,177.80 and 477.15

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Solution

The fourth proportional to 785.20, 1,177.80 and 477.15 is: 715.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.20 : 1,177.80 = 477.15 : x
  2. Step 2: Convert to fraction form
    785.20/1,177.80 = 477.15/x
  3. Step 3: Cross multiply
    785.20x = 1,177.80 × 477.15
  4. Step 4: Simplify right side
    785.20x = 561,981.38
  5. Step 5: Solve for x
    x = 561,981.38/785.20
  6. Step 6: Final answer
    x = 715.72

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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.