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Finding the Fourth Proportional to 306.80, 424.68 and 280.88

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Solution

The fourth proportional to 306.80, 424.68 and 280.88 is: 388.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    306.80 : 424.68 = 280.88 : x
  2. Step 2: Convert to fraction form
    306.80/424.68 = 280.88/x
  3. Step 3: Cross multiply
    306.80x = 424.68 × 280.88
  4. Step 4: Simplify right side
    306.80x = 119,284.12
  5. Step 5: Solve for x
    x = 119,284.12/306.80
  6. Step 6: Final answer
    x = 388.80

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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.