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Finding the Fourth Proportional to 156.03, 215.28 and 100.80

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Solution

The fourth proportional to 156.03, 215.28 and 100.80 is: 139.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    156.03 : 215.28 = 100.80 : x
  2. Step 2: Convert to fraction form
    156.03/215.28 = 100.80/x
  3. Step 3: Cross multiply
    156.03x = 215.28 × 100.80
  4. Step 4: Simplify right side
    156.03x = 21,700.22
  5. Step 5: Solve for x
    x = 21,700.22/156.03
  6. Step 6: Final answer
    x = 139.08

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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.