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Finding the Fourth Proportional to 389.51, 583.91 and 145.90

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Solution

The fourth proportional to 389.51, 583.91 and 145.90 is: 218.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.51 : 583.91 = 145.90 : x
  2. Step 2: Convert to fraction form
    389.51/583.91 = 145.90/x
  3. Step 3: Cross multiply
    389.51x = 583.91 × 145.90
  4. Step 4: Simplify right side
    389.51x = 85,193.02
  5. Step 5: Solve for x
    x = 85,193.02/389.51
  6. Step 6: Final answer
    x = 218.72

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.