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Finding the Fourth Proportional to 708.89, 978.28 and 394.18

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Solution

The fourth proportional to 708.89, 978.28 and 394.18 is: 543.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    708.89 : 978.28 = 394.18 : x
  2. Step 2: Convert to fraction form
    708.89/978.28 = 394.18/x
  3. Step 3: Cross multiply
    708.89x = 978.28 × 394.18
  4. Step 4: Simplify right side
    708.89x = 385,618.41
  5. Step 5: Solve for x
    x = 385,618.41/708.89
  6. Step 6: Final answer
    x = 543.97

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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.