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Finding the Fourth Proportional to 787.42, 1,085.98 and 663.38

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Solution

The fourth proportional to 787.42, 1,085.98 and 663.38 is: 914.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.42 : 1,085.98 = 663.38 : x
  2. Step 2: Convert to fraction form
    787.42/1,085.98 = 663.38/x
  3. Step 3: Cross multiply
    787.42x = 1,085.98 × 663.38
  4. Step 4: Simplify right side
    787.42x = 720,417.41
  5. Step 5: Solve for x
    x = 720,417.41/787.42
  6. Step 6: Final answer
    x = 914.91

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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.