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Finding the Fourth Proportional to 1,087.29, 1,500.39 and 645.21

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Solution

The fourth proportional to 1,087.29, 1,500.39 and 645.21 is: 890.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,087.29 : 1,500.39 = 645.21 : x
  2. Step 2: Convert to fraction form
    1,087.29/1,500.39 = 645.21/x
  3. Step 3: Cross multiply
    1,087.29x = 1,500.39 × 645.21
  4. Step 4: Simplify right side
    1,087.29x = 968,066.63
  5. Step 5: Solve for x
    x = 968,066.63/1,087.29
  6. Step 6: Final answer
    x = 890.35

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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.