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Finding the Fourth Proportional to 78.19, 116.75 and 77.38

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Solution

The fourth proportional to 78.19, 116.75 and 77.38 is: 115.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.19 : 116.75 = 77.38 : x
  2. Step 2: Convert to fraction form
    78.19/116.75 = 77.38/x
  3. Step 3: Cross multiply
    78.19x = 116.75 × 77.38
  4. Step 4: Simplify right side
    78.19x = 9,034.02
  5. Step 5: Solve for x
    x = 9,034.02/78.19
  6. Step 6: Final answer
    x = 115.54

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.