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Finding the Fourth Proportional to 288.78, 398.73 and 215.16

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Solution

The fourth proportional to 288.78, 398.73 and 215.16 is: 297.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.78 : 398.73 = 215.16 : x
  2. Step 2: Convert to fraction form
    288.78/398.73 = 215.16/x
  3. Step 3: Cross multiply
    288.78x = 398.73 × 215.16
  4. Step 4: Simplify right side
    288.78x = 85,790.75
  5. Step 5: Solve for x
    x = 85,790.75/288.78
  6. Step 6: Final answer
    x = 297.08

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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.