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Finding the Fourth Proportional to 318.20, 438.93 and 187.18

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Solution

The fourth proportional to 318.20, 438.93 and 187.18 is: 258.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.20 : 438.93 = 187.18 : x
  2. Step 2: Convert to fraction form
    318.20/438.93 = 187.18/x
  3. Step 3: Cross multiply
    318.20x = 438.93 × 187.18
  4. Step 4: Simplify right side
    318.20x = 82,158.92
  5. Step 5: Solve for x
    x = 82,158.92/318.20
  6. Step 6: Final answer
    x = 258.20

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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.