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Finding the Fourth Proportional to 714.12, 985.72 and 419.28

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Solution

The fourth proportional to 714.12, 985.72 and 419.28 is: 578.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    714.12 : 985.72 = 419.28 : x
  2. Step 2: Convert to fraction form
    714.12/985.72 = 419.28/x
  3. Step 3: Cross multiply
    714.12x = 985.72 × 419.28
  4. Step 4: Simplify right side
    714.12x = 413,288.72
  5. Step 5: Solve for x
    x = 413,288.72/714.12
  6. Step 6: Final answer
    x = 578.74

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.