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Finding the Fourth Proportional to 649.12, 895.64 and 387.20

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Solution

The fourth proportional to 649.12, 895.64 and 387.20 is: 534.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.12 : 895.64 = 387.20 : x
  2. Step 2: Convert to fraction form
    649.12/895.64 = 387.20/x
  3. Step 3: Cross multiply
    649.12x = 895.64 × 387.20
  4. Step 4: Simplify right side
    649.12x = 346,791.81
  5. Step 5: Solve for x
    x = 346,791.81/649.12
  6. Step 6: Final answer
    x = 534.25

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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.