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Finding the Fourth Proportional to 1,128.30, 1,557 and 630.84

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Solution

The fourth proportional to 1,128.30, 1,557 and 630.84 is: 870.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,128.30 : 1,557 = 630.84 : x
  2. Step 2: Convert to fraction form
    1,128.30/1,557 = 630.84/x
  3. Step 3: Cross multiply
    1,128.30x = 1,557 × 630.84
  4. Step 4: Simplify right side
    1,128.30x = 982,217.88
  5. Step 5: Solve for x
    x = 982,217.88/1,128.30
  6. Step 6: Final answer
    x = 870.53

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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.