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Finding the Fourth Proportional to 687.66, 947.34 and 490.74

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Solution

The fourth proportional to 687.66, 947.34 and 490.74 is: 676.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.66 : 947.34 = 490.74 : x
  2. Step 2: Convert to fraction form
    687.66/947.34 = 490.74/x
  3. Step 3: Cross multiply
    687.66x = 947.34 × 490.74
  4. Step 4: Simplify right side
    687.66x = 464,897.63
  5. Step 5: Solve for x
    x = 464,897.63/687.66
  6. Step 6: Final answer
    x = 676.06

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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.