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Finding the Fourth Proportional to 389.58, 584.40 and 142.74

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Solution

The fourth proportional to 389.58, 584.40 and 142.74 is: 214.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.58 : 584.40 = 142.74 : x
  2. Step 2: Convert to fraction form
    389.58/584.40 = 142.74/x
  3. Step 3: Cross multiply
    389.58x = 584.40 × 142.74
  4. Step 4: Simplify right side
    389.58x = 83,417.26
  5. Step 5: Solve for x
    x = 83,417.26/389.58
  6. Step 6: Final answer
    x = 214.12

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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.