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Finding the Fourth Proportional to 421.77, 581.49 and 311.25

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Solution

The fourth proportional to 421.77, 581.49 and 311.25 is: 429.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.77 : 581.49 = 311.25 : x
  2. Step 2: Convert to fraction form
    421.77/581.49 = 311.25/x
  3. Step 3: Cross multiply
    421.77x = 581.49 × 311.25
  4. Step 4: Simplify right side
    421.77x = 180,988.76
  5. Step 5: Solve for x
    x = 180,988.76/421.77
  6. Step 6: Final answer
    x = 429.12

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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.