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Finding the Fourth Proportional to 280.71, 386.91 and 215.10

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Solution

The fourth proportional to 280.71, 386.91 and 215.10 is: 296.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.71 : 386.91 = 215.10 : x
  2. Step 2: Convert to fraction form
    280.71/386.91 = 215.10/x
  3. Step 3: Cross multiply
    280.71x = 386.91 × 215.10
  4. Step 4: Simplify right side
    280.71x = 83,224.34
  5. Step 5: Solve for x
    x = 83,224.34/280.71
  6. Step 6: Final answer
    x = 296.48

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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.