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Finding the Fourth Proportional to 155.79, 215.01 and 90.28

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Solution

The fourth proportional to 155.79, 215.01 and 90.28 is: 124.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.79 : 215.01 = 90.28 : x
  2. Step 2: Convert to fraction form
    155.79/215.01 = 90.28/x
  3. Step 3: Cross multiply
    155.79x = 215.01 × 90.28
  4. Step 4: Simplify right side
    155.79x = 19,411.37
  5. Step 5: Solve for x
    x = 19,411.37/155.79
  6. Step 6: Final answer
    x = 124.60

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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.