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Finding the Fourth Proportional to 981.16, 1,471.47 and 287.70

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Solution

The fourth proportional to 981.16, 1,471.47 and 287.70 is: 431.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    981.16 : 1,471.47 = 287.70 : x
  2. Step 2: Convert to fraction form
    981.16/1,471.47 = 287.70/x
  3. Step 3: Cross multiply
    981.16x = 1,471.47 × 287.70
  4. Step 4: Simplify right side
    981.16x = 423,341.92
  5. Step 5: Solve for x
    x = 423,341.92/981.16
  6. Step 6: Final answer
    x = 431.47

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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.