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Finding the Fourth Proportional to 489.84, 731.60 and 387.24

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Solution

The fourth proportional to 489.84, 731.60 and 387.24 is: 578.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.84 : 731.60 = 387.24 : x
  2. Step 2: Convert to fraction form
    489.84/731.60 = 387.24/x
  3. Step 3: Cross multiply
    489.84x = 731.60 × 387.24
  4. Step 4: Simplify right side
    489.84x = 283,302.85
  5. Step 5: Solve for x
    x = 283,302.85/489.84
  6. Step 6: Final answer
    x = 578.36

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.