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Finding the Fourth Proportional to 971.12, 1,339.98 and 640.10

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Solution

The fourth proportional to 971.12, 1,339.98 and 640.10 is: 883.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    971.12 : 1,339.98 = 640.10 : x
  2. Step 2: Convert to fraction form
    971.12/1,339.98 = 640.10/x
  3. Step 3: Cross multiply
    971.12x = 1,339.98 × 640.10
  4. Step 4: Simplify right side
    971.12x = 857,721.20
  5. Step 5: Solve for x
    x = 857,721.20/971.12
  6. Step 6: Final answer
    x = 883.23

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.