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Finding the Fourth Proportional to 420.32, 580.56 and 317.28

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Solution

The fourth proportional to 420.32, 580.56 and 317.28 is: 438.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.32 : 580.56 = 317.28 : x
  2. Step 2: Convert to fraction form
    420.32/580.56 = 317.28/x
  3. Step 3: Cross multiply
    420.32x = 580.56 × 317.28
  4. Step 4: Simplify right side
    420.32x = 184,200.08
  5. Step 5: Solve for x
    x = 184,200.08/420.32
  6. Step 6: Final answer
    x = 438.24

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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.