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Finding the Fourth Proportional to 162.42, 243.72 and 85.38

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Solution

The fourth proportional to 162.42, 243.72 and 85.38 is: 128.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    162.42 : 243.72 = 85.38 : x
  2. Step 2: Convert to fraction form
    162.42/243.72 = 85.38/x
  3. Step 3: Cross multiply
    162.42x = 243.72 × 85.38
  4. Step 4: Simplify right side
    162.42x = 20,808.81
  5. Step 5: Solve for x
    x = 20,808.81/162.42
  6. Step 6: Final answer
    x = 128.12

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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.