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Finding the Fourth Proportional to 280.42, 387.33 and 215.71

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Solution

The fourth proportional to 280.42, 387.33 and 215.71 is: 297.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.42 : 387.33 = 215.71 : x
  2. Step 2: Convert to fraction form
    280.42/387.33 = 215.71/x
  3. Step 3: Cross multiply
    280.42x = 387.33 × 215.71
  4. Step 4: Simplify right side
    280.42x = 83,550.95
  5. Step 5: Solve for x
    x = 83,550.95/280.42
  6. Step 6: Final answer
    x = 297.95

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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.