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Finding the Fourth Proportional to 647.70, 971.87 and 318.84

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Solution

The fourth proportional to 647.70, 971.87 and 318.84 is: 478.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.70 : 971.87 = 318.84 : x
  2. Step 2: Convert to fraction form
    647.70/971.87 = 318.84/x
  3. Step 3: Cross multiply
    647.70x = 971.87 × 318.84
  4. Step 4: Simplify right side
    647.70x = 309,869.44
  5. Step 5: Solve for x
    x = 309,869.44/647.70
  6. Step 6: Final answer
    x = 478.42

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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.