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Finding the Fourth Proportional to 78.29, 117.28 and 66.02

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Solution

The fourth proportional to 78.29, 117.28 and 66.02 is: 98.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.29 : 117.28 = 66.02 : x
  2. Step 2: Convert to fraction form
    78.29/117.28 = 66.02/x
  3. Step 3: Cross multiply
    78.29x = 117.28 × 66.02
  4. Step 4: Simplify right side
    78.29x = 7,742.32
  5. Step 5: Solve for x
    x = 7,742.32/78.29
  6. Step 6: Final answer
    x = 98.89

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.