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Finding the Fourth Proportional to 714.43, 985.69 and 399.65

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Solution

The fourth proportional to 714.43, 985.69 and 399.65 is: 551.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    714.43 : 985.69 = 399.65 : x
  2. Step 2: Convert to fraction form
    714.43/985.69 = 399.65/x
  3. Step 3: Cross multiply
    714.43x = 985.69 × 399.65
  4. Step 4: Simplify right side
    714.43x = 393,929.01
  5. Step 5: Solve for x
    x = 393,929.01/714.43
  6. Step 6: Final answer
    x = 551.39

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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.