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Finding the Fourth Proportional to 280.68, 387.20 and 215.07

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Solution

The fourth proportional to 280.68, 387.20 and 215.07 is: 296.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.68 : 387.20 = 215.07 : x
  2. Step 2: Convert to fraction form
    280.68/387.20 = 215.07/x
  3. Step 3: Cross multiply
    280.68x = 387.20 × 215.07
  4. Step 4: Simplify right side
    280.68x = 83,275.10
  5. Step 5: Solve for x
    x = 83,275.10/280.68
  6. Step 6: Final answer
    x = 296.69

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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.