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Finding the Fourth Proportional to 288.40, 398.30 and 217.38

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Solution

The fourth proportional to 288.40, 398.30 and 217.38 is: 300.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.40 : 398.30 = 217.38 : x
  2. Step 2: Convert to fraction form
    288.40/398.30 = 217.38/x
  3. Step 3: Cross multiply
    288.40x = 398.30 × 217.38
  4. Step 4: Simplify right side
    288.40x = 86,582.45
  5. Step 5: Solve for x
    x = 86,582.45/288.40
  6. Step 6: Final answer
    x = 300.22

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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.