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Finding the Fourth Proportional to 212.47, 318.79 and 121.35

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Solution

The fourth proportional to 212.47, 318.79 and 121.35 is: 182.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.47 : 318.79 = 121.35 : x
  2. Step 2: Convert to fraction form
    212.47/318.79 = 121.35/x
  3. Step 3: Cross multiply
    212.47x = 318.79 × 121.35
  4. Step 4: Simplify right side
    212.47x = 38,684.04
  5. Step 5: Solve for x
    x = 38,684.04/212.47
  6. Step 6: Final answer
    x = 182.07

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.