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Finding the Fourth Proportional to 390.47, 538.72 and 233.13

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Solution

The fourth proportional to 390.47, 538.72 and 233.13 is: 321.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.47 : 538.72 = 233.13 : x
  2. Step 2: Convert to fraction form
    390.47/538.72 = 233.13/x
  3. Step 3: Cross multiply
    390.47x = 538.72 × 233.13
  4. Step 4: Simplify right side
    390.47x = 125,590.06
  5. Step 5: Solve for x
    x = 125,590.06/390.47
  6. Step 6: Final answer
    x = 321.64

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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.