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Finding the Fourth Proportional to 587.40, 809.60 and 390.56

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Solution

The fourth proportional to 587.40, 809.60 and 390.56 is: 538.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    587.40 : 809.60 = 390.56 : x
  2. Step 2: Convert to fraction form
    587.40/809.60 = 390.56/x
  3. Step 3: Cross multiply
    587.40x = 809.60 × 390.56
  4. Step 4: Simplify right side
    587.40x = 316,197.38
  5. Step 5: Solve for x
    x = 316,197.38/587.40
  6. Step 6: Final answer
    x = 538.30

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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.