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Finding the Fourth Proportional to 687.58, 948.84 and 392.89

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Solution

The fourth proportional to 687.58, 948.84 and 392.89 is: 542.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.58 : 948.84 = 392.89 : x
  2. Step 2: Convert to fraction form
    687.58/948.84 = 392.89/x
  3. Step 3: Cross multiply
    687.58x = 948.84 × 392.89
  4. Step 4: Simplify right side
    687.58x = 372,789.75
  5. Step 5: Solve for x
    x = 372,789.75/687.58
  6. Step 6: Final answer
    x = 542.18

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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.