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Finding the Fourth Proportional to 645.67, 968.78 and 316.90

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Solution

The fourth proportional to 645.67, 968.78 and 316.90 is: 475.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.67 : 968.78 = 316.90 : x
  2. Step 2: Convert to fraction form
    645.67/968.78 = 316.90/x
  3. Step 3: Cross multiply
    645.67x = 968.78 × 316.90
  4. Step 4: Simplify right side
    645.67x = 307,006.38
  5. Step 5: Solve for x
    x = 307,006.38/645.67
  6. Step 6: Final answer
    x = 475.48

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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.