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Finding the Fourth Proportional to 686.82, 947.66 and 388.02

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Solution

The fourth proportional to 686.82, 947.66 and 388.02 is: 535.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.82 : 947.66 = 388.02 : x
  2. Step 2: Convert to fraction form
    686.82/947.66 = 388.02/x
  3. Step 3: Cross multiply
    686.82x = 947.66 × 388.02
  4. Step 4: Simplify right side
    686.82x = 367,711.03
  5. Step 5: Solve for x
    x = 367,711.03/686.82
  6. Step 6: Final answer
    x = 535.38

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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.