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Finding the Fourth Proportional to 90.42, 124.80 and 61.30

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Solution

The fourth proportional to 90.42, 124.80 and 61.30 is: 84.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.42 : 124.80 = 61.30 : x
  2. Step 2: Convert to fraction form
    90.42/124.80 = 61.30/x
  3. Step 3: Cross multiply
    90.42x = 124.80 × 61.30
  4. Step 4: Simplify right side
    90.42x = 7,650.24
  5. Step 5: Solve for x
    x = 7,650.24/90.42
  6. Step 6: Final answer
    x = 84.61

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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.