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Finding the Fourth Proportional to 390.53, 538.91 and 259.77

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Solution

The fourth proportional to 390.53, 538.91 and 259.77 is: 358.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.53 : 538.91 = 259.77 : x
  2. Step 2: Convert to fraction form
    390.53/538.91 = 259.77/x
  3. Step 3: Cross multiply
    390.53x = 538.91 × 259.77
  4. Step 4: Simplify right side
    390.53x = 139,991.35
  5. Step 5: Solve for x
    x = 139,991.35/390.53
  6. Step 6: Final answer
    x = 358.47

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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.