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Finding the Fourth Proportional to 647.84, 971.40 and 387.88

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Solution

The fourth proportional to 647.84, 971.40 and 387.88 is: 581.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.84 : 971.40 = 387.88 : x
  2. Step 2: Convert to fraction form
    647.84/971.40 = 387.88/x
  3. Step 3: Cross multiply
    647.84x = 971.40 × 387.88
  4. Step 4: Simplify right side
    647.84x = 376,786.63
  5. Step 5: Solve for x
    x = 376,786.63/647.84
  6. Step 6: Final answer
    x = 581.60

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.