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Finding the Fourth Proportional to 289.48, 399.18 and 215.68

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Solution

The fourth proportional to 289.48, 399.18 and 215.68 is: 297.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.48 : 399.18 = 215.68 : x
  2. Step 2: Convert to fraction form
    289.48/399.18 = 215.68/x
  3. Step 3: Cross multiply
    289.48x = 399.18 × 215.68
  4. Step 4: Simplify right side
    289.48x = 86,095.14
  5. Step 5: Solve for x
    x = 86,095.14/289.48
  6. Step 6: Final answer
    x = 297.41

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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.