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Finding the Fourth Proportional to 90.50, 124.85 and 57.74

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Solution

The fourth proportional to 90.50, 124.85 and 57.74 is: 79.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.50 : 124.85 = 57.74 : x
  2. Step 2: Convert to fraction form
    90.50/124.85 = 57.74/x
  3. Step 3: Cross multiply
    90.50x = 124.85 × 57.74
  4. Step 4: Simplify right side
    90.50x = 7,208.36
  5. Step 5: Solve for x
    x = 7,208.36/90.50
  6. Step 6: Final answer
    x = 79.65

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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.