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Finding the Fourth Proportional to 78.65, 117.92 and 49.70

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Solution

The fourth proportional to 78.65, 117.92 and 49.70 is: 74.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.65 : 117.92 = 49.70 : x
  2. Step 2: Convert to fraction form
    78.65/117.92 = 49.70/x
  3. Step 3: Cross multiply
    78.65x = 117.92 × 49.70
  4. Step 4: Simplify right side
    78.65x = 5,859.79
  5. Step 5: Solve for x
    x = 5,859.79/78.65
  6. Step 6: Final answer
    x = 74.51

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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.