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Finding the Fourth Proportional to 712.80, 983.85 and 638.99

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Solution

The fourth proportional to 712.80, 983.85 and 638.99 is: 881.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    712.80 : 983.85 = 638.99 : x
  2. Step 2: Convert to fraction form
    712.80/983.85 = 638.99/x
  3. Step 3: Cross multiply
    712.80x = 983.85 × 638.99
  4. Step 4: Simplify right side
    712.80x = 628,665.39
  5. Step 5: Solve for x
    x = 628,665.39/712.80
  6. Step 6: Final answer
    x = 881.97

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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.