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Finding the Fourth Proportional to 289.54, 399.45 and 215.86

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Solution

The fourth proportional to 289.54, 399.45 and 215.86 is: 297.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.54 : 399.45 = 215.86 : x
  2. Step 2: Convert to fraction form
    289.54/399.45 = 215.86/x
  3. Step 3: Cross multiply
    289.54x = 399.45 × 215.86
  4. Step 4: Simplify right side
    289.54x = 86,225.28
  5. Step 5: Solve for x
    x = 86,225.28/289.54
  6. Step 6: Final answer
    x = 297.80

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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.