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Finding the Fourth Proportional to 831.91, 1,248 and 312.09

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Solution

The fourth proportional to 831.91, 1,248 and 312.09 is: 468.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    831.91 : 1,248 = 312.09 : x
  2. Step 2: Convert to fraction form
    831.91/1,248 = 312.09/x
  3. Step 3: Cross multiply
    831.91x = 1,248 × 312.09
  4. Step 4: Simplify right side
    831.91x = 389,488.32
  5. Step 5: Solve for x
    x = 389,488.32/831.91
  6. Step 6: Final answer
    x = 468.19

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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.