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Finding the Fourth Proportional to 288.90, 398.79 and 209.25

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Solution

The fourth proportional to 288.90, 398.79 and 209.25 is: 288.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.90 : 398.79 = 209.25 : x
  2. Step 2: Convert to fraction form
    288.90/398.79 = 209.25/x
  3. Step 3: Cross multiply
    288.90x = 398.79 × 209.25
  4. Step 4: Simplify right side
    288.90x = 83,446.81
  5. Step 5: Solve for x
    x = 83,446.81/288.90
  6. Step 6: Final answer
    x = 288.84

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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.