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Finding the Fourth Proportional to 390.70, 538.07 and 382.20

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Solution

The fourth proportional to 390.70, 538.07 and 382.20 is: 526.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.70 : 538.07 = 382.20 : x
  2. Step 2: Convert to fraction form
    390.70/538.07 = 382.20/x
  3. Step 3: Cross multiply
    390.70x = 538.07 × 382.20
  4. Step 4: Simplify right side
    390.70x = 205,647.66
  5. Step 5: Solve for x
    x = 205,647.66/390.70
  6. Step 6: Final answer
    x = 526.36

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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.