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Finding the Fourth Proportional to 100.94, 139.29 and 57.28

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Solution

The fourth proportional to 100.94, 139.29 and 57.28 is: 79.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.94 : 139.29 = 57.28 : x
  2. Step 2: Convert to fraction form
    100.94/139.29 = 57.28/x
  3. Step 3: Cross multiply
    100.94x = 139.29 × 57.28
  4. Step 4: Simplify right side
    100.94x = 7,978.53
  5. Step 5: Solve for x
    x = 7,978.53/100.94
  6. Step 6: Final answer
    x = 79.04

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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.