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Finding the Fourth Proportional to 630.82, 870.78 and 421.18

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Solution

The fourth proportional to 630.82, 870.78 and 421.18 is: 581.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    630.82 : 870.78 = 421.18 : x
  2. Step 2: Convert to fraction form
    630.82/870.78 = 421.18/x
  3. Step 3: Cross multiply
    630.82x = 870.78 × 421.18
  4. Step 4: Simplify right side
    630.82x = 366,755.12
  5. Step 5: Solve for x
    x = 366,755.12/630.82
  6. Step 6: Final answer
    x = 581.39

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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.