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Finding the Fourth Proportional to 708.91, 978.29 and 398.41

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Solution

The fourth proportional to 708.91, 978.29 and 398.41 is: 549.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    708.91 : 978.29 = 398.41 : x
  2. Step 2: Convert to fraction form
    708.91/978.29 = 398.41/x
  3. Step 3: Cross multiply
    708.91x = 978.29 × 398.41
  4. Step 4: Simplify right side
    708.91x = 389,760.52
  5. Step 5: Solve for x
    x = 389,760.52/708.91
  6. Step 6: Final answer
    x = 549.80

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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.