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Finding the Fourth Proportional to 785.57, 1,178.22 and 285.20

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Solution

The fourth proportional to 785.57, 1,178.22 and 285.20 is: 427.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.57 : 1,178.22 = 285.20 : x
  2. Step 2: Convert to fraction form
    785.57/1,178.22 = 285.20/x
  3. Step 3: Cross multiply
    785.57x = 1,178.22 × 285.20
  4. Step 4: Simplify right side
    785.57x = 336,022.45
  5. Step 5: Solve for x
    x = 336,022.45/785.57
  6. Step 6: Final answer
    x = 427.74

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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.