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Finding the Fourth Proportional to 865.45, 1,298.71 and 688.71

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Solution

The fourth proportional to 865.45, 1,298.71 and 688.71 is: 1,033.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    865.45 : 1,298.71 = 688.71 : x
  2. Step 2: Convert to fraction form
    865.45/1,298.71 = 688.71/x
  3. Step 3: Cross multiply
    865.45x = 1,298.71 × 688.71
  4. Step 4: Simplify right side
    865.45x = 894,434.56
  5. Step 5: Solve for x
    x = 894,434.56/865.45
  6. Step 6: Final answer
    x = 1,033.49

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1.5x scale

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.