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Finding the Fourth Proportional to 420.12, 578.48 and 320.63

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Solution

The fourth proportional to 420.12, 578.48 and 320.63 is: 441.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.12 : 578.48 = 320.63 : x
  2. Step 2: Convert to fraction form
    420.12/578.48 = 320.63/x
  3. Step 3: Cross multiply
    420.12x = 578.48 × 320.63
  4. Step 4: Simplify right side
    420.12x = 185,473.55
  5. Step 5: Solve for x
    x = 185,473.55/420.12
  6. Step 6: Final answer
    x = 441.48

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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.