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Finding the Fourth Proportional to 100.40, 140.80 and 100.40

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Solution

The fourth proportional to 100.40, 140.80 and 100.40 is: 140.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.40 : 140.80 = 100.40 : x
  2. Step 2: Convert to fraction form
    100.40/140.80 = 100.40/x
  3. Step 3: Cross multiply
    100.40x = 140.80 × 100.40
  4. Step 4: Simplify right side
    100.40x = 14,136.32
  5. Step 5: Solve for x
    x = 14,136.32/100.40
  6. Step 6: Final answer
    x = 140.80

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.