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Finding the Fourth Proportional to 421.80, 581.88 and 247

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Solution

The fourth proportional to 421.80, 581.88 and 247 is: 340.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.80 : 581.88 = 247 : x
  2. Step 2: Convert to fraction form
    421.80/581.88 = 247/x
  3. Step 3: Cross multiply
    421.80x = 581.88 × 247
  4. Step 4: Simplify right side
    421.80x = 143,724.36
  5. Step 5: Solve for x
    x = 143,724.36/421.80
  6. Step 6: Final answer
    x = 340.74

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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.