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Finding the Fourth Proportional to 714.30, 985.74 and 399.58

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Solution

The fourth proportional to 714.30, 985.74 and 399.58 is: 551.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    714.30 : 985.74 = 399.58 : x
  2. Step 2: Convert to fraction form
    714.30/985.74 = 399.58/x
  3. Step 3: Cross multiply
    714.30x = 985.74 × 399.58
  4. Step 4: Simplify right side
    714.30x = 393,878.03
  5. Step 5: Solve for x
    x = 393,878.03/714.30
  6. Step 6: Final answer
    x = 551.42

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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.