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Finding the Fourth Proportional to 90.09, 124.31 and 51.28

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Solution

The fourth proportional to 90.09, 124.31 and 51.28 is: 70.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.09 : 124.31 = 51.28 : x
  2. Step 2: Convert to fraction form
    90.09/124.31 = 51.28/x
  3. Step 3: Cross multiply
    90.09x = 124.31 × 51.28
  4. Step 4: Simplify right side
    90.09x = 6,373.74
  5. Step 5: Solve for x
    x = 6,373.74/90.09
  6. Step 6: Final answer
    x = 70.75

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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.