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Finding the Fourth Proportional to 871.97, 1,308.02 and 643.68

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Solution

The fourth proportional to 871.97, 1,308.02 and 643.68 is: 965.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.97 : 1,308.02 = 643.68 : x
  2. Step 2: Convert to fraction form
    871.97/1,308.02 = 643.68/x
  3. Step 3: Cross multiply
    871.97x = 1,308.02 × 643.68
  4. Step 4: Simplify right side
    871.97x = 841,943.10
  5. Step 5: Solve for x
    x = 841,943.10/871.97
  6. Step 6: Final answer
    x = 965.57

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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.