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Finding the Fourth Proportional to 821.70, 1,133.70 and 490.34

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Solution

The fourth proportional to 821.70, 1,133.70 and 490.34 is: 676.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.70 : 1,133.70 = 490.34 : x
  2. Step 2: Convert to fraction form
    821.70/1,133.70 = 490.34/x
  3. Step 3: Cross multiply
    821.70x = 1,133.70 × 490.34
  4. Step 4: Simplify right side
    821.70x = 555,892.79
  5. Step 5: Solve for x
    x = 555,892.79/821.70
  6. Step 6: Final answer
    x = 676.52

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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.