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Finding the Fourth Proportional to 124.70, 186.86 and 78.45

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Solution

The fourth proportional to 124.70, 186.86 and 78.45 is: 117.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    124.70 : 186.86 = 78.45 : x
  2. Step 2: Convert to fraction form
    124.70/186.86 = 78.45/x
  3. Step 3: Cross multiply
    124.70x = 186.86 × 78.45
  4. Step 4: Simplify right side
    124.70x = 14,658.77
  5. Step 5: Solve for x
    x = 14,658.77/124.70
  6. Step 6: Final answer
    x = 117.56

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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.