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Finding the Fourth Proportional to 130.85, 180.53 and 78.40

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Solution

The fourth proportional to 130.85, 180.53 and 78.40 is: 108.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    130.85 : 180.53 = 78.40 : x
  2. Step 2: Convert to fraction form
    130.85/180.53 = 78.40/x
  3. Step 3: Cross multiply
    130.85x = 180.53 × 78.40
  4. Step 4: Simplify right side
    130.85x = 14,153.55
  5. Step 5: Solve for x
    x = 14,153.55/130.85
  6. Step 6: Final answer
    x = 108.17

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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.