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Finding the Fourth Proportional to 1,290.25, 1,781.76 and 898.35

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Solution

The fourth proportional to 1,290.25, 1,781.76 and 898.35 is: 1,240.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,290.25 : 1,781.76 = 898.35 : x
  2. Step 2: Convert to fraction form
    1,290.25/1,781.76 = 898.35/x
  3. Step 3: Cross multiply
    1,290.25x = 1,781.76 × 898.35
  4. Step 4: Simplify right side
    1,290.25x = 1,600,644.10
  5. Step 5: Solve for x
    x = 1,600,644.10/1,290.25
  6. Step 6: Final answer
    x = 1,240.57

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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.