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Finding the Fourth Proportional to 61.28, 91.16 and 58.40

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Solution

The fourth proportional to 61.28, 91.16 and 58.40 is: 86.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.28 : 91.16 = 58.40 : x
  2. Step 2: Convert to fraction form
    61.28/91.16 = 58.40/x
  3. Step 3: Cross multiply
    61.28x = 91.16 × 58.40
  4. Step 4: Simplify right side
    61.28x = 5,323.74
  5. Step 5: Solve for x
    x = 5,323.74/61.28
  6. Step 6: Final answer
    x = 86.88

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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.