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Finding the Fourth Proportional to 785.06, 1,178.67 and 420.02

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Solution

The fourth proportional to 785.06, 1,178.67 and 420.02 is: 630.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.06 : 1,178.67 = 420.02 : x
  2. Step 2: Convert to fraction form
    785.06/1,178.67 = 420.02/x
  3. Step 3: Cross multiply
    785.06x = 1,178.67 × 420.02
  4. Step 4: Simplify right side
    785.06x = 495,064.97
  5. Step 5: Solve for x
    x = 495,064.97/785.06
  6. Step 6: Final answer
    x = 630.61

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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.