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Finding the Fourth Proportional to 420.69, 580.47 and 255.00

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Solution

The fourth proportional to 420.69, 580.47 and 255.00 is: 351.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.69 : 580.47 = 255.00 : x
  2. Step 2: Convert to fraction form
    420.69/580.47 = 255.00/x
  3. Step 3: Cross multiply
    420.69x = 580.47 × 255.00
  4. Step 4: Simplify right side
    420.69x = 148,017.81
  5. Step 5: Solve for x
    x = 148,017.81/420.69
  6. Step 6: Final answer
    x = 351.84

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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.