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Finding the Fourth Proportional to 66.78, 99.68 and 58.28

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Solution

The fourth proportional to 66.78, 99.68 and 58.28 is: 86.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.78 : 99.68 = 58.28 : x
  2. Step 2: Convert to fraction form
    66.78/99.68 = 58.28/x
  3. Step 3: Cross multiply
    66.78x = 99.68 × 58.28
  4. Step 4: Simplify right side
    66.78x = 5,809.35
  5. Step 5: Solve for x
    x = 5,809.35/66.78
  6. Step 6: Final answer
    x = 86.99

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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.