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Finding the Fourth Proportional to 99.30, 148.27 and 78.78

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Solution

The fourth proportional to 99.30, 148.27 and 78.78 is: 117.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.30 : 148.27 = 78.78 : x
  2. Step 2: Convert to fraction form
    99.30/148.27 = 78.78/x
  3. Step 3: Cross multiply
    99.30x = 148.27 × 78.78
  4. Step 4: Simplify right side
    99.30x = 11,680.71
  5. Step 5: Solve for x
    x = 11,680.71/99.30
  6. Step 6: Final answer
    x = 117.63

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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.