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Finding the Fourth Proportional to 98.90, 148.31 and 34.78

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Solution

The fourth proportional to 98.90, 148.31 and 34.78 is: 52.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    98.90 : 148.31 = 34.78 : x
  2. Step 2: Convert to fraction form
    98.90/148.31 = 34.78/x
  3. Step 3: Cross multiply
    98.90x = 148.31 × 34.78
  4. Step 4: Simplify right side
    98.90x = 5,158.22
  5. Step 5: Solve for x
    x = 5,158.22/98.90
  6. Step 6: Final answer
    x = 52.16

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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.