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Finding the Fourth Proportional to 1,079.84, 1,489.29 and 686.72

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Solution

The fourth proportional to 1,079.84, 1,489.29 and 686.72 is: 947.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,079.84 : 1,489.29 = 686.72 : x
  2. Step 2: Convert to fraction form
    1,079.84/1,489.29 = 686.72/x
  3. Step 3: Cross multiply
    1,079.84x = 1,489.29 × 686.72
  4. Step 4: Simplify right side
    1,079.84x = 1,022,725.23
  5. Step 5: Solve for x
    x = 1,022,725.23/1,079.84
  6. Step 6: Final answer
    x = 947.11

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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.