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Finding the Fourth Proportional to 710.31, 980.12 and 399.75

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Solution

The fourth proportional to 710.31, 980.12 and 399.75 is: 551.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    710.31 : 980.12 = 399.75 : x
  2. Step 2: Convert to fraction form
    710.31/980.12 = 399.75/x
  3. Step 3: Cross multiply
    710.31x = 980.12 × 399.75
  4. Step 4: Simplify right side
    710.31x = 391,800.97
  5. Step 5: Solve for x
    x = 391,800.97/710.31
  6. Step 6: Final answer
    x = 551.59

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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.