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Finding the Fourth Proportional to 686.41, 947.05 and 406.76

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Solution

The fourth proportional to 686.41, 947.05 and 406.76 is: 561.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.41 : 947.05 = 406.76 : x
  2. Step 2: Convert to fraction form
    686.41/947.05 = 406.76/x
  3. Step 3: Cross multiply
    686.41x = 947.05 × 406.76
  4. Step 4: Simplify right side
    686.41x = 385,216.31
  5. Step 5: Solve for x
    x = 385,216.31/686.41
  6. Step 6: Final answer
    x = 561.21

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Half scale
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Double scale
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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.