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Finding the Fourth Proportional to 785.02, 1,178.07 and 420.07

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Solution

The fourth proportional to 785.02, 1,178.07 and 420.07 is: 630.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.02 : 1,178.07 = 420.07 : x
  2. Step 2: Convert to fraction form
    785.02/1,178.07 = 420.07/x
  3. Step 3: Cross multiply
    785.02x = 1,178.07 × 420.07
  4. Step 4: Simplify right side
    785.02x = 494,871.86
  5. Step 5: Solve for x
    x = 494,871.86/785.02
  6. Step 6: Final answer
    x = 630.39

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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.