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Finding the Fourth Proportional to 648.65, 971.07 and 428.87

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Solution

The fourth proportional to 648.65, 971.07 and 428.87 is: 642.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.65 : 971.07 = 428.87 : x
  2. Step 2: Convert to fraction form
    648.65/971.07 = 428.87/x
  3. Step 3: Cross multiply
    648.65x = 971.07 × 428.87
  4. Step 4: Simplify right side
    648.65x = 416,462.79
  5. Step 5: Solve for x
    x = 416,462.79/648.65
  6. Step 6: Final answer
    x = 642.05

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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.