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Finding the Fourth Proportional to 280.68, 386.64 and 215.16

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Solution

The fourth proportional to 280.68, 386.64 and 215.16 is: 296.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.68 : 386.64 = 215.16 : x
  2. Step 2: Convert to fraction form
    280.68/386.64 = 215.16/x
  3. Step 3: Cross multiply
    280.68x = 386.64 × 215.16
  4. Step 4: Simplify right side
    280.68x = 83,189.46
  5. Step 5: Solve for x
    x = 83,189.46/280.68
  6. Step 6: Final answer
    x = 296.39

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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.