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Finding the Fourth Proportional to 647.39, 971.13 and 389.15

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Solution

The fourth proportional to 647.39, 971.13 and 389.15 is: 583.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.39 : 971.13 = 389.15 : x
  2. Step 2: Convert to fraction form
    647.39/971.13 = 389.15/x
  3. Step 3: Cross multiply
    647.39x = 971.13 × 389.15
  4. Step 4: Simplify right side
    647.39x = 377,915.24
  5. Step 5: Solve for x
    x = 377,915.24/647.39
  6. Step 6: Final answer
    x = 583.75

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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.