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Finding the Fourth Proportional to 787.50, 1,086.75 and 438.20

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Solution

The fourth proportional to 787.50, 1,086.75 and 438.20 is: 604.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.50 : 1,086.75 = 438.20 : x
  2. Step 2: Convert to fraction form
    787.50/1,086.75 = 438.20/x
  3. Step 3: Cross multiply
    787.50x = 1,086.75 × 438.20
  4. Step 4: Simplify right side
    787.50x = 476,208.42
  5. Step 5: Solve for x
    x = 476,208.42/787.50
  6. Step 6: Final answer
    x = 604.71

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1.5x scale

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.