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Finding the Fourth Proportional to 785.12, 1,177.80 and 477.20

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Solution

The fourth proportional to 785.12, 1,177.80 and 477.20 is: 715.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.12 : 1,177.80 = 477.20 : x
  2. Step 2: Convert to fraction form
    785.12/1,177.80 = 477.20/x
  3. Step 3: Cross multiply
    785.12x = 1,177.80 × 477.20
  4. Step 4: Simplify right side
    785.12x = 562,046.16
  5. Step 5: Solve for x
    x = 562,046.16/785.12
  6. Step 6: Final answer
    x = 715.87

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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.