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Finding the Fourth Proportional to 787.70, 1,087.05 and 438.39

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Solution

The fourth proportional to 787.70, 1,087.05 and 438.39 is: 605.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.70 : 1,087.05 = 438.39 : x
  2. Step 2: Convert to fraction form
    787.70/1,087.05 = 438.39/x
  3. Step 3: Cross multiply
    787.70x = 1,087.05 × 438.39
  4. Step 4: Simplify right side
    787.70x = 476,551.85
  5. Step 5: Solve for x
    x = 476,551.85/787.70
  6. Step 6: Final answer
    x = 605.00

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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.