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Finding the Fourth Proportional to 420.65, 580.74 and 281.00

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Solution

The fourth proportional to 420.65, 580.74 and 281.00 is: 387.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.65 : 580.74 = 281.00 : x
  2. Step 2: Convert to fraction form
    420.65/580.74 = 281.00/x
  3. Step 3: Cross multiply
    420.65x = 580.74 × 281.00
  4. Step 4: Simplify right side
    420.65x = 163,188.34
  5. Step 5: Solve for x
    x = 163,188.34/420.65
  6. Step 6: Final answer
    x = 387.94

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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.