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Finding the Fourth Proportional to 648.32, 971.40 and 455

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Solution

The fourth proportional to 648.32, 971.40 and 455 is: 681.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.32 : 971.40 = 455 : x
  2. Step 2: Convert to fraction form
    648.32/971.40 = 455/x
  3. Step 3: Cross multiply
    648.32x = 971.40 × 455
  4. Step 4: Simplify right side
    648.32x = 441,987
  5. Step 5: Solve for x
    x = 441,987/648.32
  6. Step 6: Final answer
    x = 681.74

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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.