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Finding the Fourth Proportional to 156.40, 215.94 and 101.28

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Solution

The fourth proportional to 156.40, 215.94 and 101.28 is: 139.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    156.40 : 215.94 = 101.28 : x
  2. Step 2: Convert to fraction form
    156.40/215.94 = 101.28/x
  3. Step 3: Cross multiply
    156.40x = 215.94 × 101.28
  4. Step 4: Simplify right side
    156.40x = 21,870.40
  5. Step 5: Solve for x
    x = 21,870.40/156.40
  6. Step 6: Final answer
    x = 139.84

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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.