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Finding the Fourth Proportional to 655.40, 904.47 and 389.87

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Solution

The fourth proportional to 655.40, 904.47 and 389.87 is: 538.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    655.40 : 904.47 = 389.87 : x
  2. Step 2: Convert to fraction form
    655.40/904.47 = 389.87/x
  3. Step 3: Cross multiply
    655.40x = 904.47 × 389.87
  4. Step 4: Simplify right side
    655.40x = 352,627.01
  5. Step 5: Solve for x
    x = 352,627.01/655.40
  6. Step 6: Final answer
    x = 538.03

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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.