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Finding the Fourth Proportional to 74.70, 102.78 and 71.46

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Solution

The fourth proportional to 74.70, 102.78 and 71.46 is: 98.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.70 : 102.78 = 71.46 : x
  2. Step 2: Convert to fraction form
    74.70/102.78 = 71.46/x
  3. Step 3: Cross multiply
    74.70x = 102.78 × 71.46
  4. Step 4: Simplify right side
    74.70x = 7,344.66
  5. Step 5: Solve for x
    x = 7,344.66/74.70
  6. Step 6: Final answer
    x = 98.32

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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.