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Finding the Fourth Proportional to 390.59, 538.99 and 215.93

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Solution

The fourth proportional to 390.59, 538.99 and 215.93 is: 297.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.59 : 538.99 = 215.93 : x
  2. Step 2: Convert to fraction form
    390.59/538.99 = 215.93/x
  3. Step 3: Cross multiply
    390.59x = 538.99 × 215.93
  4. Step 4: Simplify right side
    390.59x = 116,384.11
  5. Step 5: Solve for x
    x = 116,384.11/390.59
  6. Step 6: Final answer
    x = 297.97

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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.