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Finding the Fourth Proportional to 912.08, 1,258.21 and 787.71

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Solution

The fourth proportional to 912.08, 1,258.21 and 787.71 is: 1,086.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    912.08 : 1,258.21 = 787.71 : x
  2. Step 2: Convert to fraction form
    912.08/1,258.21 = 787.71/x
  3. Step 3: Cross multiply
    912.08x = 1,258.21 × 787.71
  4. Step 4: Simplify right side
    912.08x = 991,102.63
  5. Step 5: Solve for x
    x = 991,102.63/912.08
  6. Step 6: Final answer
    x = 1,086.65

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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.