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Finding the Fourth Proportional to 459.40, 690.06 and 387.40

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Solution

The fourth proportional to 459.40, 690.06 and 387.40 is: 581.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    459.40 : 690.06 = 387.40 : x
  2. Step 2: Convert to fraction form
    459.40/690.06 = 387.40/x
  3. Step 3: Cross multiply
    459.40x = 690.06 × 387.40
  4. Step 4: Simplify right side
    459.40x = 267,329.24
  5. Step 5: Solve for x
    x = 267,329.24/459.40
  6. Step 6: Final answer
    x = 581.91

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.