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Finding the Fourth Proportional to 390.45, 538.59 and 297.21

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Solution

The fourth proportional to 390.45, 538.59 and 297.21 is: 409.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.45 : 538.59 = 297.21 : x
  2. Step 2: Convert to fraction form
    390.45/538.59 = 297.21/x
  3. Step 3: Cross multiply
    390.45x = 538.59 × 297.21
  4. Step 4: Simplify right side
    390.45x = 160,074.33
  5. Step 5: Solve for x
    x = 160,074.33/390.45
  6. Step 6: Final answer
    x = 409.97

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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.