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Finding the Fourth Proportional to 688.92, 948.96 and 643.56

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Solution

The fourth proportional to 688.92, 948.96 and 643.56 is: 886.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.92 : 948.96 = 643.56 : x
  2. Step 2: Convert to fraction form
    688.92/948.96 = 643.56/x
  3. Step 3: Cross multiply
    688.92x = 948.96 × 643.56
  4. Step 4: Simplify right side
    688.92x = 610,712.70
  5. Step 5: Solve for x
    x = 610,712.70/688.92
  6. Step 6: Final answer
    x = 886.48

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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.