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Finding the Fourth Proportional to 288.90, 398.58 and 215.34

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Solution

The fourth proportional to 288.90, 398.58 and 215.34 is: 297.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.90 : 398.58 = 215.34 : x
  2. Step 2: Convert to fraction form
    288.90/398.58 = 215.34/x
  3. Step 3: Cross multiply
    288.90x = 398.58 × 215.34
  4. Step 4: Simplify right side
    288.90x = 85,830.22
  5. Step 5: Solve for x
    x = 85,830.22/288.90
  6. Step 6: Final answer
    x = 297.09

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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.