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Finding the Fourth Proportional to 718.68, 991.28 and 571

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Solution

The fourth proportional to 718.68, 991.28 and 571 is: 787.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.68 : 991.28 = 571 : x
  2. Step 2: Convert to fraction form
    718.68/991.28 = 571/x
  3. Step 3: Cross multiply
    718.68x = 991.28 × 571
  4. Step 4: Simplify right side
    718.68x = 566,020.88
  5. Step 5: Solve for x
    x = 566,020.88/718.68
  6. Step 6: Final answer
    x = 787.58

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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.