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Finding the Fourth Proportional to 288.70, 398.40 and 157.70

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Solution

The fourth proportional to 288.70, 398.40 and 157.70 is: 217.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.70 : 398.40 = 157.70 : x
  2. Step 2: Convert to fraction form
    288.70/398.40 = 157.70/x
  3. Step 3: Cross multiply
    288.70x = 398.40 × 157.70
  4. Step 4: Simplify right side
    288.70x = 62,827.68
  5. Step 5: Solve for x
    x = 62,827.68/288.70
  6. Step 6: Final answer
    x = 217.62

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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.