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Finding the Fourth Proportional to 124.30, 171.48 and 85.42

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Solution

The fourth proportional to 124.30, 171.48 and 85.42 is: 117.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    124.30 : 171.48 = 85.42 : x
  2. Step 2: Convert to fraction form
    124.30/171.48 = 85.42/x
  3. Step 3: Cross multiply
    124.30x = 171.48 × 85.42
  4. Step 4: Simplify right side
    124.30x = 14,647.82
  5. Step 5: Solve for x
    x = 14,647.82/124.30
  6. Step 6: Final answer
    x = 117.84

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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.