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Finding the Fourth Proportional to 100.71, 137.90 and 100.40

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Solution

The fourth proportional to 100.71, 137.90 and 100.40 is: 137.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.71 : 137.90 = 100.40 : x
  2. Step 2: Convert to fraction form
    100.71/137.90 = 100.40/x
  3. Step 3: Cross multiply
    100.71x = 137.90 × 100.40
  4. Step 4: Simplify right side
    100.71x = 13,844.66
  5. Step 5: Solve for x
    x = 13,844.66/100.71
  6. Step 6: Final answer
    x = 137.47

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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.