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Finding the Fourth Proportional to 71.40, 98 and 69.80

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Solution

The fourth proportional to 71.40, 98 and 69.80 is: 95.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.40 : 98 = 69.80 : x
  2. Step 2: Convert to fraction form
    71.40/98 = 69.80/x
  3. Step 3: Cross multiply
    71.40x = 98 × 69.80
  4. Step 4: Simplify right side
    71.40x = 6,840.40
  5. Step 5: Solve for x
    x = 6,840.40/71.40
  6. Step 6: Final answer
    x = 95.80

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.