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Finding the Fourth Proportional to 718.86, 989.96 and 686.06

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Solution

The fourth proportional to 718.86, 989.96 and 686.06 is: 944.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.86 : 989.96 = 686.06 : x
  2. Step 2: Convert to fraction form
    718.86/989.96 = 686.06/x
  3. Step 3: Cross multiply
    718.86x = 989.96 × 686.06
  4. Step 4: Simplify right side
    718.86x = 679,163.58
  5. Step 5: Solve for x
    x = 679,163.58/718.86
  6. Step 6: Final answer
    x = 944.78

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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.