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Finding the Fourth Proportional to 710.05, 979.88 and 399.55

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Solution

The fourth proportional to 710.05, 979.88 and 399.55 is: 551.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    710.05 : 979.88 = 399.55 : x
  2. Step 2: Convert to fraction form
    710.05/979.88 = 399.55/x
  3. Step 3: Cross multiply
    710.05x = 979.88 × 399.55
  4. Step 4: Simplify right side
    710.05x = 391,511.05
  5. Step 5: Solve for x
    x = 391,511.05/710.05
  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.