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Finding the Fourth Proportional to 288.80, 398.40 and 214.88

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Solution

The fourth proportional to 288.80, 398.40 and 214.88 is: 296.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.80 : 398.40 = 214.88 : x
  2. Step 2: Convert to fraction form
    288.80/398.40 = 214.88/x
  3. Step 3: Cross multiply
    288.80x = 398.40 × 214.88
  4. Step 4: Simplify right side
    288.80x = 85,608.19
  5. Step 5: Solve for x
    x = 85,608.19/288.80
  6. Step 6: Final answer
    x = 296.43

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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.