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Finding the Fourth Proportional to 820.53, 1,230.39 and 430.47

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Solution

The fourth proportional to 820.53, 1,230.39 and 430.47 is: 645.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.53 : 1,230.39 = 430.47 : x
  2. Step 2: Convert to fraction form
    820.53/1,230.39 = 430.47/x
  3. Step 3: Cross multiply
    820.53x = 1,230.39 × 430.47
  4. Step 4: Simplify right side
    820.53x = 529,645.98
  5. Step 5: Solve for x
    x = 529,645.98/820.53
  6. Step 6: Final answer
    x = 645.49

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.