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Finding the Fourth Proportional to 438.66, 605.61 and 390.06

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Solution

The fourth proportional to 438.66, 605.61 and 390.06 is: 538.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.66 : 605.61 = 390.06 : x
  2. Step 2: Convert to fraction form
    438.66/605.61 = 390.06/x
  3. Step 3: Cross multiply
    438.66x = 605.61 × 390.06
  4. Step 4: Simplify right side
    438.66x = 236,224.24
  5. Step 5: Solve for x
    x = 236,224.24/438.66
  6. Step 6: Final answer
    x = 538.51

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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.