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Finding the Fourth Proportional to 156.19, 215.54 and 90.70

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Solution

The fourth proportional to 156.19, 215.54 and 90.70 is: 125.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    156.19 : 215.54 = 90.70 : x
  2. Step 2: Convert to fraction form
    156.19/215.54 = 90.70/x
  3. Step 3: Cross multiply
    156.19x = 215.54 × 90.70
  4. Step 4: Simplify right side
    156.19x = 19,549.48
  5. Step 5: Solve for x
    x = 19,549.48/156.19
  6. Step 6: Final answer
    x = 125.16

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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.