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Finding the Fourth Proportional to 971.84, 1,340.25 and 640.14

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Solution

The fourth proportional to 971.84, 1,340.25 and 640.14 is: 882.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    971.84 : 1,340.25 = 640.14 : x
  2. Step 2: Convert to fraction form
    971.84/1,340.25 = 640.14/x
  3. Step 3: Cross multiply
    971.84x = 1,340.25 × 640.14
  4. Step 4: Simplify right side
    971.84x = 857,947.64
  5. Step 5: Solve for x
    x = 857,947.64/971.84
  6. Step 6: Final answer
    x = 882.81

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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.