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Finding the Fourth Proportional to 78.21, 116.48 and 74.09

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Solution

The fourth proportional to 78.21, 116.48 and 74.09 is: 110.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.21 : 116.48 = 74.09 : x
  2. Step 2: Convert to fraction form
    78.21/116.48 = 74.09/x
  3. Step 3: Cross multiply
    78.21x = 116.48 × 74.09
  4. Step 4: Simplify right side
    78.21x = 8,630.26
  5. Step 5: Solve for x
    x = 8,630.26/78.21
  6. Step 6: Final answer
    x = 110.35

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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.